How do I get MIUI to allow notifications for reminder apps?

Question

I'm using an MI phone (Redmi Note 4G), it runs on MIUI v7. This is a problem that a lot of people have been facing for a really long time now: Push notifications for reminder apps (Say Wunderlist, Google Keep, Any.Do etc.) don't work. Mostly they don't work at all, sometimes they are delayed for random number of minutes / hours for absolutely no reason.

How do I get MIUI to allow these notifications?

Here is what I've tried:

1. I've tried "locking" the apps into the apps tray (So that when I clear the RAM, that particular app isn't cleared )

Result: Doesn't work.

2. I've given all permissions to the concerned apps. Even those permissions that were obviously not required for the app to do it's basic task: Remind me of my to-dos.

Doesn't work.

3. I've made sure that I've enabled allnotifications in both the MIUI settings and in the settings of the app

Doesn't work.

There is only thing that does work: Not force closing the app (by pressing the back button for a few seconds). Even if I do so, the reminders only work fine for a few minutes: say for half-an-hour or an hour. Reminders that come up later than that don't work.

Here is an ongoing discussion on the same topic: http://en.miui.com/thread-19270-1-1.html (miui forum)

Answer 1

On MIUI 8, under Settings, Permissions, you can add individual apps to Autostarts. This is the only thing that worked for apps that I wanted to keep running in the background (eg Gentle Alarm).

The permission does more than autostart an app 'cos if I don't have that permission set for Gentle Alarm and start the app manually, the app doesn't work, so I think the term 'autostart' is misleading.

The other thing you might need to do is tell MIUI to not apply any battery saving methods (depending on the MIUI version).

Having said all this, I can't get Google Now to work. I guess I need to find the right app/module to enable in Autostarts.