Is there any place, onsite or off, that lists the items that each past monthly collection contains? I’ve done some poking around here and some googling but haven’t been able to turn anything useful up, and I’d like to be able to check if there’s something I want in a previous collection before I actually get it. It might just be that my search engine skills are lacking?

Subetalodge lists them :)

oh my god, thank you. i've been slowly easing back into Subeta after a long time away, and it's been a trip figuring out what is and isn't still there, and I'd completely forgotten about SubetaLodge. This is exactly what i needed.

Cheers!

There is also this forum post but it's not updated to the 2020 collections and some may be missing. This is just an extra reference for you. :)

awesome, thank you! I'll bookmark that also, I appreciate it.

The excellent says on her profile she's been working overtime lately. That's probably why we haven't been seeing that updated. She often also pastes the past years of the month in question in comments for the News for the most recent collection and she wasnt' around to do that one either.