while checking steam guides I randomly came across a bit about there being more to the crossroads dungeon which I thought I finished a couple days ago
turns out there's a little more content accessible by swimming through some flooded tunnels and lo and behold, I found a seemingly-unique artifact (which just gives you the pretty bad debuff of taking damage from contact with water, but it seems to be a quest item so idk might come in handy later on), and also the "sewer thing" that seems to be somewhat of a mascot among the community
that sewer thing just straight up trades you a refillable eather canister for 6 blue mushrooms which I found a short distance from there, and that's kinda huge considering an eather canister was the one thing I needed to start having fun with the really gimmicky artifacts (summoning ghosts to fight off enemies and turning npcs on your side to troll enemy squads)
oh yeah also I guess I also wanted a canister for boring serious reasons like powering one of the best sidearms I found and eventually to do the game's version of fast travel, when I find another artifact I don't have yet
I haven't actually got the canister yet cause on my way back, I had my hands full with the hydrophobic artifact from earlier so I couldn't swim to where I needed, and I didn't wanna go back after stashing the artifact either cause I need to sleep now so ig I'll do that tomorrow