@slh made a suggestion for possible mt76 devices: https://forum.openwrt.org/t/top-ten-routers-currently-in-use/30199/4
mt7621
Xiaomi Mi Router 3g (mir3g)
ZBT WE1326
ZBT WG3526
…
You could also have a look at the OpenWrt firmware image download statistics and see which image files for mt76 are popular downloads: https://downloads.openwrt.org/stats/
HTH