while the Matrix protocol technically supports perfect forward secrecy, Element does not currently use it.
No kidding? I thought that was one of the few things that set them apart from the others. Do you have any sources for that, preferably their own documentation
ETA: StackOverflow concurs that if you have encryption on a chat or group, PFS comes along with it due to the Olm protocol being heavily inspired by the Signal one.
Element itself says “It is based on Olm, an implementation of the Double Ratchet protocol popularised by Signal”, but it’s not totally clear how “based on” it is. Wouldn’t it just be Olm(/Megolm)?