Dr Gerard Bulger:
Torrc allows you to exit from a different IP. I thought it a good idea to stop arbitrary blocking of the advertised Tor exit IP, the captchas and blacklists that tor users suffer. When IPv6 implemented fully we have a wide range of IPs to send from on each server.
Perhaps it is not considered good form to do so as the internet should know who is using Tor.
So what is the problems for TOR security when exits set up to send from a different IP? Is it that we do not know what the second IP is up to in dealing with the IP4 traffic from the exit?
simplified: there can be two reasons for inbound (OR) IP != exit IP:
a) the exit used https://2019.www.torproject.org/docs/tor-manual.html.en#OutboundBindAddressE... or some form of NAT
b) the exit relay uses an tor client to route its traffic back into tor
This exit was doing (b), I think you are referring to (a) which is perfectly fine.