the upper south cave, the north east cave, the caverns of lost hope, the caverns of lost faith and the tek cave are not on mobile, and they don't spawn at the swamp cave or snow cave. i found them in the north west cave, and besides the terrifying cliffs, it was pretty ok. just take some bug repellent and warm armor. and they just sit in certain spots in clusters. the only other creatures in there are araneos, so with a few bug repellents, it's actually pretty easy, but without them the clusters of bats and spiders can be dangerous. you can avoid the cliffs if you don't care about the artifact, but unfortunately if you do want that, you'll have to brave at least one cliff. the cave entrance is so small that i couldn't get my onyc out, so i had to request it.
You can absolutely tame them through a wall still. Just finished a 145 tame with mutton, because kibble does not work. Build a 3x1 hallway with no walls on either end, agro run through place a wall in front of it, run around and wall it off. Barely derender, feed through the wall. 21 mutton for a 150, 4.5% per feed. ♡Hz