Tap-to-pay is an obstacle for GrapheneOS adoption for sure. It seems like some Garmin watches have tap-to-pay support which doesn’t just utilize your phone like other smart watches. I’m going to be heading in that direction soon. I’ve found some reports that the Vivoactiv series actually loads the card onto the watch so I’d use the Garmin app in a secondary profile to set it up but then largely leave the Garmin watch disconnected from my phone but should still be able to use the watch for tap-to-pay.