I am on Catalina and see `hazelworker` memory consumption grow and grow, I usually restart the service when it gets to ~1.6-1.9GB as that is when it starts becoming noticeable as my laptop becomes memory bound. It ends up being the highest memory consuming process on my system, both by total memory and by Private Memory detail.
This seems to occur within ~3-days of previously restarting it, I have been having issues with my system having kernel panics due to out of memory issues and am wondering if Hazel is a contributing factor. I had similar issues with Hazel 4 and had a launchd script that would just restart Hazel daily to avoid it.
My rule set is very limited and very basic, probably not even enough to truly justify paying for Hazel

The only "complex" rule I have is one that calls an embedded AppleScript, the rest are all very basic single folder actions against individual files.