Dirty-flashed (download ROM, boot to TWRP, install, clear cache/dalvik) my Mi Max 2 several hours ago from last MIUI 9 Dev ROM 8.4.26 to MIUI 10 8.7.26, everything is fine except :
1. Known bug (and reported here several times) the More menu doesn't show in Gallery app, not a big deal, rarely use that menu myself.
2. All notes in Notes app are deleted (might want to backup your notes before upgrading from MIUI 9 to 10)
3. Picture quality in Camera app reset to Standard, this may be the reason why some people are saying MIUI 10 camera is not as good as MIUI 9.
I run all installed apps on my Mi Max 2 after upgraded to MIUI 10, all of them run without problem.
Magisk v16 works fine, SafetyNet check success, Camera2 api works, *no-support-for-this-app-on-this-forum* works, overall I must say 8.7.26 is a good weekly ROM (cannot comment on previous MIUI 10 weeklies since this is my first MIUI 10 weekly).
One more thing, after several hours of usage, battery backup seems to be better on this weekly ROM compared to MIUI 9 v8.4.26 (I did reboot my phone twice after upgrading to MIUI 10), hopefully it will stay this way after days.