[SOLUTION AT END OF POST]
Hello again. A few days ago I made the post in the link above which is about getting Silent Hunter 3 working with the LSH3 megamod, and I got a great answer in there to use steamtinkerlaunch to run separate executables just once (e.g. to install JSGME mod manager and to install the actual megamod LSH3).
After playing for a bit I decided I want a little more control over what mods are installed, and decided to switch to the GWX megamod, so I completely uninstalled SH3 and its folder in the steamapps/common folder, and reinstalled it cleanly. Then using wine I ran the 4GB patch so that the game would use 4GB instead of 2GB memory which is required for running many mods. The memory usage can get quite high. After that I loaded all my desired mods with JSGME.
The game starts fine, and I can do all the training missions and the single missions, but I cant start a campaign. After the loading bar for entering a campaign patrol fills up, there is a delay of a couple minutes (normal for GWX as during that stage it is loading all its mods and any other mods you have enabled), and then crashes to desktop. This clearly means that it is running out of memory while loading mods. However after running the patcher to increase the memory limit of the executable I get a new sh3.exe file and my original gets renamed to sh3.exe.Backup, which seems to show that the patch has been applied correctly.
Could anyone help me diagnose this issue please?
Thanks in advance!
Edit 1 (SOLUTION): So what ended up working for me was simply making the game run using proton 6.3-8. I did try version 4.3 as well, but that didnt seem to be working that well with the widegui mod I have. Thanks to all who gave suggestions!
Edit 2: Editing to add 2 more things to the solution. Because of frequent crashes while in the career patrol, I ended up lowering the Particle Density to 90 and also do not create any saves while out on patrol. Not sure which of the two actually stopped the crashing, but so far I've played for about 20 hours with no crash.
What does protondb say? Any help there?
Yeap, I ended up looking there and there were hints to use certain proton versions buried in the reports. Will update my OP now with the solution. Thanks!