However now that I'm trying to set up Pis for actual use (previously had set up a test environment to validate using them) I'm running into major performance issues once certmonger starts. Using a systemd timer to delay start until everything else starts at least lets everything else FreeIPA related start up and work, but once certmonger starts it still hammers the system using tons of memory and causing lots of swapping.

Is there any reason for it to spawn so many processes all at once, versus doing them in a more serial fashion? And did something change in FreeIPA/certmonger behavior in the last year that would cause such a performance regression in memory limited scenarios? Previously I just had zram swap and it was fine, now I have to replace that with actual swap on storage.

Also, there's currently no certs needing renewal or anything on this system, so why does it even spawn so many processes ? 

Eventually these complete and things settle down but it takes a very long time, and without delaying certmonger until after the rest of FreeIPA it can cause various IPA services to take so long that they die and fail to start.