I have this issue as well. For now I have disabled all garage functions and the problem has stopped. The long loading screen specifically started when the alt+1 option of viewing the quests was installed. There is no option in the installer to turn off this option. so the only way to fix it is to turn off all garage mods.
I installed OMC modpack after a couple of days of frustration, and it ran fine until they added the alt+1 option of viewing active quests to their modpack with no option not to use. OMC then started having the same garage loading screen issue.
I, of course am back to using Aslain since I prefer it and OMC is causing the same issue for me. If at all possible is there a way we can get the option to disable this feature in the installer? It is not linked to the automatic quest update choice since I never checked that one to begin with. I prefer to see what my next quest is when I activate it.
Unfortunately, I am not computer literate enough to try to isolate the files or do debug, I would probably break the internet as a whole if I tried any of that stuff :)
I greatly appreciate anything that can be done. I miss the ability to see how much xp I need until the next tank at a glance, and am looking forward to being able to use that function again.
Keep up the awesome work.