jim via Tor Project Forum:
Hi Gus,
I am currently running two instances, they currently both run as guards, but what I have noticed is that as soon as a relay gets a guard flag that the number of circuit requests and onion skins gets dropped. I would like the ability to only run one guard, with my other instance to run just as a middle node - as this would reduce the demand on the system resources - and therefore allow me to manage the stability of my host(s).
That drop in circuit requests (and onion skins) is probably expected.
See the blog post about the lifecycle of a relay,
The lifecycle of a new relay | The Tor Project, in particular
phase 3