I'm afraid, I still have this problem mentioned in the other thread. The last 3 times I tried to start the game, it froze directly before the mooneye logo could even come up...

Same here.
It happened after ALT+tabbing out of the loading scene (to do something else while the game was loading) in Fullscreen Window mode. To fix it, I closed to GOG client and searched for "Lost Ember" on Windows to start the game "directly". This fixed it for me.