Yea just sharing my anecdote since not a lot on google about it. My thought is it’s probably some combo of the CPU and Mobo not liking the level of cold. There was a Linus tech tips video on overclocking with liquid nitrogen and one of the quirks is computer won’t boot till you warm it up again.
My tinfoil hat theory is something in the mobo/cpu self shorts/disconnects when too cold and just depends on the silicone quality you get for that number of cold before it needs the hairdryer treatment.
I had a similar issue until I bought a different PSU that was slightly higher capacity. Not sure if it was some cold start GPU power draw quirk but that’s the only thing I changed and haven’t had a problem since.
Most of the classes, races, and backgrounds are forms with various modifiers you can add/remove/tweak in the UI. So those won’t need any real coding unless you’re trying to do something REALLY custom like a new mechanic that doesn’t exist in DND core at all. I think a good example of really custom would be a star shaped spell area of effect. Possible to do, just might need to get a module or code one yourself if no one else has.
For the system rules those are harder to edit and you will need to code for that. If you can make your modifications work in roll20 though I would be surprised if you couldn’t do that in foundry.
Honestly the biggest selling point for me was the plug-ins/modules the community can make. I would take a peek at some of those as they’re such a game changer compared to roll20 and the other vtt’s I’ve used.
I’ve been running games on foundry for 2-3 years and don’t think you’ll have issues with custom classes, races, or backgrounds unless you are doing something really really wild.
The core mechanical changes are going to be harder, but compared to roll20 it wouldn’t even be a competition foundry is just better for customization.
The most annoying thing is probably going to be porting all your homebrew. You can share it between worlds though via compendiums which is a nice timesaver.
Hopefully they’ve come a long way since this talk, but hearing about the situation in 2016 I’m not surprised: https://youtu.be/7KXVox0-7lU?si=fHaxSKvw5MIlg__2
Adjusting the game to fit your table is the hardest challenge of all unfortunately. There are some players who don’t fit certain tables and DM styles and it’s your job to either make it work or tell them to find another table.
I think in your case you can make it work, but you’ve got a lot of work to do since you’re trying to accommodate a carebear happy fun time player at a table you want to run more and more as “hardcore-lite” experience.
I think two ideas I would have for you are to present your hardcore challenges as optional / non lethal challenges in a arena type colosseum. This lets you design difficult encounters but sandboxes them from consequences. If you want there to be consequences you’re going to make the carebear sad.
Another option is to come up with a McGuffin for the carebear that acts as protection for their character. E.g they fail there death saves and they turn into a rampaging monster due to some story reason. Lots of bad things happen to the party, but carebear wakes up the next day fine. You can use this to change the dynamic of “carebear” go frontline while we hit badguy. The big problem here is protecting the carebear leads to possible resentment from the other players so doing something like this is dangerous overall, but it can work depending on your players and how you do it.
For a TLDR I think you want to run more hard core games and your “carebear” player no longer fits at the table you want to run. In short you have to accommodate the “carebear”, change their mindset, or create a table of people ok with a more hardcore game.