There is different firmware sets for the aAK and ES models. So if you have both boards, you’d have to load firmware when you swapped them. So sorry, yes swappable but not that convenient. Also, they didn’t allow any space where the OP amps are located, so you can’t put your opamps on an extension board. Meaning that you are constantly pulling up on the fragile legs. Would have been nice if they left a few millimeters more of space for that. T1 sounds good though, so I won’t knock that.