After a lot of unpairing/pairing, restore backup / fresh install, ... I finally managed to install beta 2 (was stuck on beta 1 for 2 days, impossible to upgrade due to intempestive Apple Logo on the watch and/or "not connected to Internet" verification error).
But now on beta 2, I've the same issue I had with beta 1: from time to time, the watch only display the Apple logo (but still responds to the iPhone's query information from the General/Information page).
Only thing I can do is force reboot it, and pray it don't go to Apple logo too quickly after boot so I can use it at least a little bit to test my code... what a shame!
Not sure if it's related or not, but many applications (including stock Weather app) are not fully installed.
When trying to use Weather complication, it says that the app is not on the watch and should be installed from the AppStore... problem is it's NOT on the store (and the iPhone Weather app is installed on my phone).
Also, when trying to reinstall other non-stock apps, it stays stuck at a full "installation circle" on the phone, and greyed logo on the watch itself. Even avec a reboot.
So maybe that Apple Logo thing is related to the watch trying to directly access Weather without checks, and then crashing to death.
Someone has an idea on how to fully restore apps on the watch, without having to unpair/pair or reset to defaults since I already did this at least 10 times today, without any more luck?