On a trimmed-down progs.dat with only essential URQP fixes (e.g. megahealth rot, fish count, walkframe leak, door unlock sound) since I consider it bloated with all those extra options Maddes added which almost nobody would use. At least in singleplayer, which is what I am interested in. Based on Preach's cleaned-up QC 1.06 source.

Compared to the progs.dat I am using in the vanilla fixes or AMQ, it's shaving off at least 60 KB of extra code. Doesn't sound like much, but it's all about what you really need. 

That's crazy I was thinking about the same thing today. I took those fixes for SMP 2021.11 from Quake Info Pool and then URQP.

I realized it would have been better to start there and strip stuff out but it's too late for my project. Good luck. 

About how to add Deathmatch modes 3-5 to vanilla code? Even though I am focussed on SP changes, I think this is something that should be in, anyway. 

Up for review here:

ID1 cleaned source + selected URQP fixes (1 MB)

I would really appreciate if anyone with profound QC knowledge did a thorough review of all the fixes I applied. Everything compiles just fine, but I might still have made some mistake(s). Especially the DM stuff couldn't be tested.

All edits should be sufficiently commented. If you want to see a complete list of all changes, please look into progs_fixed.src (which you also need for compiling the fixed version, progs.src only gives you cleaned up code without any other changes).

BTW: I added a few fixes going beyond URQP.