It's only an issue if openresolv is installed instead of classic/slim resolvconf, and it caused other issues already like restarting Unbound every time an RA with changed info is received. Basically it doesn't seem to work well at all with setups where a local resolver is meant to be used by the network instead of by the local host only.
So instead of working around all the issues that openresolv causes, what about replacing it with resolvconf when installed as part of the Pi-hole installer?