> From the Tor Relay Guide:
>
> "Note: You can only run two Tor relays per public IPv4 address. If you
> want to run more than two relays you will need more IPv4 addresses."
> https://community.torproject.org/relay/relays-requirements/
>

Why was it decided to allow only two relays per IP address?
Is there a technical reason?

Oh and the sentence on the website: "There should be no problem at all with this requirement (all commercially available servers come with at least one IPv4 address)." is not true anymore.
An increasing amount of provider these days only give you IPv6 (or you pay much more for only one IPv4).