Was there ever a conversion for the Starfinder classes? I have a 3rd party pdf called Arcforge that reads like this was done, but it seems like I have to do the heavy lifting.
Do you mean a conversion from Starfinder to Pathfinder 1E? I'm not aware of anything official, but I haven't been looking for that either
Yes,pretty much. Arcforge has Pathfinder archetypes for Starfinder classes. I do not see a comprehensive conversion though.