I lurk and sometimes comment in a trans only sub. It is a hobby of mine.
Why would you do such a thing?
Because there I could be myself but still belong to a bigger group.
You shouldn't participate in an online community for trans people if you aren't trans yourself. At least be honest with your own gender so that you aren't being deceitful.
If a cis person participates in a chat room, they will be called out as a lurker.
Why not find a group where you can be yourself and not have to hide your own identity? Don't you think that would be more enjoyable?