Amazfit has announced that it now supports trade-ins via the web-store it operates for US consumers. The new program may thus offer a way to sort out what to do with their old smartwatch (which may not need to be from the same brand) while getting the GTR 4 or GTS 4 of their dreams at the same time. Then again, the initiative comes with caveats, not the least of which is the time-limit on its availability.