Is this homebrew "Firemind Dragonborn" race overpowered?

Question

I found this homebrew "Firemind Dragonborn" race on Dungeon Master's Guild (It was almost immediately taken down for some reason). It represents an Izzet Guild member given the Gift of Draconic Rebirth by the ancient dragon Niv-Mizzet. I'd like to know how well it compares to existing races, perhaps with Detect Balance (which I'm not able to access). Also, note that the Ability Score Increase is +2/+1 or +1/+1/+1, similar to the newer races. Without further ado, here is the race:

Firemind Dragonborn

Creature Type. You are a Humanoid.

Size. You are Medium or Small.

Speed. Your walking speed is 30 feet.

Izzet Ancestry. You have advantage on saving throws to maintain concentration on spells.

Cantrip Arsenal. You learn one of the following cantrips: fire bolt, ray of frost, or shocking grasp. Your spellcasting ability for this cantrip is Intelligence, Wisdom, or Charisma modifier (choose one when you select this race).

Draconic Resistance. You have resistance to one of the following damage types: cold, fire, lightning, or thunder (choose one when you select this race).

Undistracted. You have advantage on saving throws you make to avoid or end the charmed condition on yourself.

Languages. You can speak, read, and write Common, Draconic, and one other language of your choice.

Izzet Ingenuity. Starting at 5th level, you specialize your innate abilities. Choose one of the following traits:

• Arcane Chemistry. When you cast a spell that deals acid, cold, fire, lightning, or thunder damage, you can use your reaction to change that spell's damage to cold, fire, lightning, or thunder.
• Warded Scales. You gain resistance to one additional damage type from your Draconic Resistance trait. You gain another one at 10th level, and the last one at 15th level. At 20th level you gain resistance to psychic damage.
• Polymath Spells. Choose one 1st level, one 2nd level, and one 3rd level spell from the list below. You always have these spells prepared, and they don’t count against the number of spells you can prepare each day. You can cast these spells using any spell slots you have of the appropriate level.
  • 1st Level: detect magic, shield, thunderwave
  • 2nd Level: enlarge/reduce, flaming sphere, hold person
  • 3rd Level: counterspell, lightning bolt, slow

At an initial glance, this seems balanced. Also, note that Arcane Chemistry initially stated that it worked on "elemental damage", but I replaced this with the five types of damage commonly considered "elemental".

Answer 1

This is on the strong side

Here's your tally for the standard ones:

• Standard ASI 12 points
• Standard creature type 0 points
• Standard size and speed 0 points
• Izzet Ancestry Advantage on a situational roll 2 points, depending how much you concentrate; if you optimize your character for always casting concentration spells, could be up to "for a common roll", 4 points. I'll use the average of 3 points
• Cantrip Arsenal Cantrip, 2 points
• Draconic Resistance Resistance to a common damage type (as you can pick a common one), 4 points
• Undistracted Advantage on a rare roll, 1 point
• Languages: Common + 2 or 3 languages, 1 point

Izzet Ingenuity

This is non-standard and gives you a lot of options.

• Arcane Chemistry. Hard to price, effectively this allows you to ignore common resistances in fire, cold and lightning by always picking thunder, which is very rarely resisted. There are many monsters with such resistances, and in consequence this can add a lot of damage against them. I'd think this is at least worth 4 points.
• Warded Scales is worth at least 4 points for the other common resistance, and later on 3 points for lightning, 2 for thunder, and 2 for psychic. These latter ones we should discount, as you may or may not get there, and you only have them for a shorter part of your adventuring life. I'd rate them at 2 points for lightning, 1 for thunder, for a total of 7 points.
• Polymath Spells is nice, as preparation slots are often more limiting than spell selection for wizards, but it does not give you additional slots to cast them, so it should be worth less than features that give you spells with the slot. Those are priced at 2, 3, 3 for a 1st, 2nd and 3rd level spell, so this probably is not worth more than at most 5 points in total.

As you can pick any of them, the flexibility is also worth something, but even ignoring this, the best of these gives you 7 points, and you can pick that.

This gives us 12 + 0 + 0 + 0 + 3 + 2 + 4 + 1 + 1 + 7 = 28 points.

Average of the PHB races is 25 points. Detect Balance recommends

The recommended score for new homebrew races is 24 to 27. Races should generally not eclipse 30 or fall below 20.

So this is just outside of the recommended range, but if you discounted the later resistances more, or if you assume that concentration checks are not common, it would dip into the recommended range. In addition, if you only play to 15th level or lower, the race is only worth 26 points. So I think it's OK, a bit on the strong side.

Answer 2

Most of it is alright, but some abilities can be big

This race seems mostly balanced. Most of its abilities are common and unimpactful and it doesn't have too many abilities either. However a few of the abilities, while not being outright broken, could become problematic in some cirumstances, which I will explain below.

Izzet Ancestry

First of, this is completely useless to any non-spellcasting class. To a spellcaster however this can be incredibly useful, though depending on how often you use concentration spells. But since concentration is a core feature of spellcasting and is specifically used to balance out stronger spells, you will probably use it more often than not. This isn't outright broken, but is in my opinion something an official race would never give you.

Arcane Chemistry

This is in effect a stronger version of the Sorcerer's Transmuted Spell for Tasha's Cauldron. That ability is unique to a certain class and costs a resource of which you only have as many as you have levels per day. While Arcane Chemistry enables you to change your spell's damage type an unlimited amout of types. This is really situational and whether or not it becomes a problem depends on the type of monster' your DM throws at you and how they interact with those damage types and if you as a player know these interactions or can get to know them. E.g. if every monster has a weakness to one of those 5 types and you know it, it effectively doubles your damage output, which would be incredibly broken, while if all the monsters take neutral damage from those 5 types this ability is effectivily useless for you.

If you and your DM wanted to balance this, I would suggest making it so it can either only be used once per short rest or a number of times equal to your proficiency bonus per long rest. And to make it less complicated I would also suggest you ditch the use of a reaction, as it is really unusual for any ability to use your reaction for something you do on your turn and either make that a bonus action or have it cost no action at all, just like the Sorcerer ability it is similar to.

Warded Scales

This is interestingly the only of the three chooseable abilities that is of any use to a non-spellcaster. Getting a resistance from a race is no big deal, but getting 5(!) resistances from it is absolutely unheard of. Even 3 different damage resistances would be a lot. Players at level 20 are usually incredibly powerful anyway, so it might not make a big difference, but still 5 permanent, innate damage resistances is probably nothing any level 20 character can achieve otherwise. I also would like to note that races typically never give you new abilities after level 5, so getting new abilities from your race at levels 10, 15 and 20 is by itself already a big deal.