Thank you for the feedback, please submit a bug report here for the first issue.
The flickering issue is currently under investigation, apologies for the inconvenience caused.
Thanks for the reply, I left a bug report, even though the issue seem quite random - now I can't get it to work on 16.3.2 either anymore. The profile works first time I start the game, and overwrites the global settings. Second time I start it it takes a few seconds extra and the computer freezes a little, but no settings get applied. Third time it starts up as normal, and still no settings get applied.
I also tried the latest 16.6 and it's the same there.