Hi @radh-pmac, I choose to upgrade to the latest version possible (at the time I started to work on the upgrade for pyRevit 5) to align with the upstream active support lifecycle.
While technically simpler than with the previous version, it is still a burden to support multiple versions for packages that should have been updated to support the newer pythons.
I might have some notes lying around on how to add a new engine, I’ll get back to you when I find them