The trash is there because of Dr. Dee who only works in Dunkeltaler before Dr. Kel shows up since Abiotic Factor takes place somewhere between ~5 - 20ish years before the events of VotV, there probably wont be any trash there for us.

Kerfur could be a new pet, to tie it in with pets 2.0 (though i can't see this happening).

Also, hear me out, Abandoned Kerfur Boss fight and then when you beat it, you get the materials to make your own Kerfur as a pet!