After much incredibly fruitless painstaking efforts to mount the tyre, I am ready to try anything.

My rims are LightBicycle Falcon Wheelset AR56 Road/CX RR56C03. (rim brakes)
External Rim Width: 28mm
Internal Rim Width: 21.6mm
ETRTO 622mm. Tubeless-ready. Hooked.
This rims listed on the website is a 30mm external width, 28mm external width is a "special order".
(https://www.lightbicycle.com/700C-V-shape-56mm-depth-hand-built-carbon-road-wheels---30mm-wide-and-tubeless-compatible.html)

My tyres are Vittoria Corsa Graphene 2.0.
Width: 25mm
700c. Clinchers with tan sidewalls. I'm using inner tubes.

I can never push the remaining ~20cm worth of tyre up over the rim. This is all I have tried so far.

1. The classic pushing the mounted side to provide some give to the unmounted side.
2. Removing rim tape so allow more give.
3. Removing inner tube, just mounting the tyre itself.
4. 3 broken plastic tyre levers.
5. Cable tie on the edges on the unmounted side, to prevent more of the tyre being unseated when pushing one side up. All 5 cable ties broke.
6. Bead wax on rim brake track to aid the tyre slip up and over. (horrendously messy job)

I don't think I'm a noob in mounting tyres too. I've worked with GP5000 clinchers and tubeless, Gatorskins, old school Mavic Yksions and Panaracers in 20mm widths, on aluminium rims and carbon rims.
As per LightBicycle, Vittoria seems to top their "difficulty to mount" chart.
https://www.lightbicycle.com/newsletter/Road-Bike-Tire-Width-Charts.html

When I asked LightBicycle directly, the help I received was some links to their guide. (which is obviously not quite as useful)
Tips and Tricks for Seating Tubeless Tires

How To Install A Tight Tire Easily (Gatorskin 23c on R45)

The worst part is I'm planning to add some lead weights on the bed of the rim, which will definitely increase the tension in the tyre when mounting.

But, all hope's not lost yet. The silver lining is the tyre is definitely mountable as I am able to mount both sidewalls individually over the rim. Just that both sidewalls over the rim is currently impossible.

David Arthur's previous article reported that "Mounting up these clinchers is super-simple, and such a supple tyre can easily be done without the aid of levers."
(https://road.cc/content/review/263308-vittoria-corsa-fold-g20-tyre)

The more I drop into the rabbit hole, the more comments on how difficult it is to mount this tyre I see. Many claim that the tyres need to be stretched overnight first, but how do I stretch the tyre when it's impossible to get over the rim?

Please give me some advice, I'm near desperation at this point, typing this with raw palms from pushing the tyres.

My only qualms is METAL tyre levers. It's something I truly want to avoid using on carbon rims.

Thanks you guys!