Well, the fact that it shows this error about "trigger_allpalyers" tells me it's loading my progs.dat but I can trying changing something else too.

I'm putting it in id1\, inside a progs.pak file and I run with the Ironwail engine (but I believe progs.dat should be supported by literally every Quake port). 

That error message actually tells you the opposite of what you think it does. It tells you about something your MAP contains. The error means the mod you are running does not contain trigger_allplayers - which is probably because you are running the vanilla quake mod and not your custom one.

I would recommend creating a new mod folder under quake called "allplayers", put the progs.dat file in that folder, then run Ironwail with the -game allplayers command line switch. That should ensure you are actually running your custom mod.