ExitRelay configuration option is confusingly named
I imagine this is already well known, and that the option is very unlikely to change names, but I wish to identify the issue regardless. Perhaps the consideration of phasing in a new option with a more descriptive name is valid.
As I understand, the ExitRelay config option applies to non-exit relays in addition to exit relays. It is not considered for bridge relays (which are by definition non-exit and in a separate classification entirely).
This is confusing when configuring a non-exit, non-bridge relay. The confusion can be avoided by renaming the option to e.g. "AllowTraffic" or "AllowExitingTraffic" (or "AllowOutbound"/"Traffic" ... "...Outgoing...").
It seems the ExitRelay option is intended to be more of a safety switch to accommodate a transition in Tor concepts (the addition of bridge relays, I believe) without introducing breaking changes, rather than actually having anything to do with establishing a configured relay as an "exit" relay, as one might easily misunderstand.