Here’s something esoteric that I haven’t had to do before. First confirm your configuration:

# run show config

Scroll down and note the original peer you want to change:

peer WishThisWasPFSense.example.com {
    [...]
}

Then:

# rename peer <OLDPEER> to peer <NEWPEER>
# commit
# save

I’m not a network engineer, so please don’t ask for more details. I’m just glad you can rename; I’d assumed I’d have to make a new peer then delete the old one.

OrionVM includes VyOS as a software defined network template, and aside from my subtle dig above, it’s a capable and rock solid router from our experience.