The server i'm on blocks all part messages and replaces them with "reason filtered"
Is there a way to work around that so that the part message is displayed?

Bypassing rules is a good way to be banned. Doing it again is a good way to be permanently banned. If you really want to say something when you leave, you can just say it before leaving.

Some IRCds have modes which filter out part/quit messages in channels.

But you're saying the server is doing it... (I can think of at least one or two which do this.)


Either way, the answer is no.

I'm a tad intrigued as to why you want to see people's part messages.