Alex Haydock:
If you plan to grow further it can be handy to preemptively create relay keys so you don't have to touch all relays every time you add a new one.
Is there a guide on how this can be done? - for the benefit of other relay operators who might want to do something like this.
The steps to generate relay keys can be found here:
https://lists.torproject.org/pipermail/tor-relays/2017-January/011601.html