Yes, it is fully compatible with Lemmy, plus:

• PeerTube compatibility - you can subscribe to channels, watch videos, vote and comment them,
• feeds (essentially multireddit),
• flairs, both for posts and users,
• events and polls,
• following people, e.g. from Mastodon.

PieFed is opinionated by default, so in place of flagship piefed.social I will rather recommend piefed.zip as it federated more widely than former (just like lemmy.zip) and removes much of default roadblocks.

Or you can try Quokk.au, which apparently made some improvements in their fork of PieFed.

Recommend feddit.uk for them. You are welcome.