Did you change to a different cassette size? I tried the Derailleur hanger extenders but in the end found much better performance from a new derailleur made for wide range cassettes.

Yeah, went from the stock 14-28t to one with a 34t granny gear. I wondered about how the extender would affect performance, but maybe I’ll just try one for now and then do a proper overhaul in the near future, since the drivetrain is all original.