That still won't do contactless payments, at least I don't think so.
It's a neat idea, to just move the chip. The final result isn't pretty, it would have been way cooler if the whole thing had fitted inside the watch, but there's not a lot of room in an F-91W.
Maybe someone with more experience with antenna designs could find a way to use the backplate as part of the antenna.
That still won't do contactless payments, at least I don't think so.
It's a neat idea, to just move the chip. The final result isn't pretty, it would have been way cooler if the whole thing had fitted inside the watch, but there's not a lot of room in an F-91W.
Maybe someone with more experience with antenna designs could find a way to use the backplate as part of the antenna.