Fair enough, but I think that's a limitation of Github rather than a problem imposed by Percy.
How is that not a problem imposed by Percy?
I'd feel more comfortable having a different mechanism to request an invite.
While the permissions don't grant Code Access, it does ask to read Organization and Team membership. I'd expose data for every member of my companies github organization to Percy, JUST for an invite.
However:
Sign up for Service != Sign up for Invite.
And yes it's a GitHub limitation, we request some limited readonly access and no code access (we don't need it).