Yes, the update from 2 to 3 is difficult due to the new ORM. Updating to 4 should be vastly easier. The main functional thing that’s changed (depending on exactly which version of 3 you’re using) is that all the stuff that’s deprecated in v3 is removed in v4. So, turn on deprecation notices, run v3, and fix all of those. Once that’s done, updating to 4 should be straight forward.