The 1. Case you listed is not applicable really. We all know eink is not made for gaming.
That said 2,3 are exactly the issue of majority of android Apps, and this is not because of Eink, but but because of Android. Android toolkit is not designed for eink.
This is why companies like remarkable design their own software and open sourced their product so that users can write their own.
2,3 are non-existent on Remarkable because they do not used flawed software model such as Android, which is why I think onyx needs to step up its game, at least with regard to openness.
There is much potential with eink, and it is all hindered by the that we have been closed in the android environment. Give us the access to the source code, and I guarantee community will make Onyx the best eink platform that there is.
Otherwise, sadly, I will still use my onyx max 2, but at the same time I will be eagerly expecting the release of large remarkable (which is bound to happen). Spending 1000$ on such a horrible software experience is not an experience I would repeat.
The hard truth is that onyx products from 6 years ago were better: I still use my old onyx boox m92, and its UI is simply better - because it was designed for eink.