kivy, which does the same thing, has been around for over 10 years. I built my thesis in it a few years ago. not recommended—too many limitations and build issues in practice. given that this one is less mature...I'm not optimistic.
I tried using Kivy some years ago and also found it pretty painful. Flet I've been using for a while now and find it a joy by comparison, and it's actively developed, with a release every couple months or so. With the stability of v1.0 I expect that to slow a bit though, as I'd say at least core Flet is feature complete.
All software has limitations, that's why we keep writing more software.
Kivy is great, and the contributors are friendlier than most. I particularly like it for Android, but it's definitely way up there in terms of "easy reliable multiplatform python framework".
It also gives you a ton of options for how you want to use it, more than one way to skin a cat philosophy.