My initial thought is that there are apps for iOS and Android
in addition to being able to play in browser on mobile.
Maybe another comment is that if you do go to the trouble to set up another interface to play on OGS from mobile, one could consider instead trying to update the OGS codebase directly. It’s possible that people might be interested in helping you.
Still though I suppose if you want more creative freedom from the ground up, go for it.
I don’t know your answer about whether the api lags, but probably there’s some other threads that might be useful like
Indeed, OGS web does at least attempt to be mobile-friendly. Let me know if you’re interested in contributing in that way and need help getting started!
Regarding the topic of lag, there should be no significant lag from being on a separate domain, but you may run into CSRF issues. They can be resolved, but it does take some additional knowledge to understand what it’s for and how to work around it.