Kenp, like you I don't recall there being obvious divergence on the JP seats, and I don't recall it ever being mentioned to me as either a stude or an instructor. Certainly if there was one it wasn't big enough to be obvious when you did the seat checks. Of course canting the seats would have resulted in one or both being sat "off vertical.
Ken S, re the comment about Gemini ejections I think it was Tom Stafford who said that due the fact they had been saturated in O2 for some time if they had of ejected they would looked like firecrackers.