So I have the same problem as original poster.
Mac running 10.13.4. PoE 1 bought on Apple Store. PoE 2 bought on GOG. Found the original, complete save game. Imported to PoE2 Save games folder at ~Library/Application Support/Pillars of Eternity/Saved Games. Restarted computer. Went through the increasingly boring intro. Sat down in the chair, and still a "no saved games found" dialog shows up. It would be nice if there were a manual option to find the save.