My experiences with Raphie:
He always shows up on your first long rest after you talk to Nettie and she fail to cure you which can happen super early in the game.
He shows up in the first long rest after meeting Korrine if you haven't meet him yet (this seems to override Shadowheart's camp Temple-triggered scene might I add or maybe I didn't get it because I didn't trigger the village one, not sure).
He does not show up if you kill the 3 leaders, free Haslin and then go do the Underdark following the party (never talked to Nettie). The only content I haven't done in that character was the Hag and some minor encounters in the Underdark (I did talk to the Society of Brilliance, did the quest and got the mind-shielding ring). I had cleared the Gith patrol before freeing Haslin too. Zero Raphie and the ending EA cinematic support never meeting him too.
