If in UK and can find T-56/ZYXEL EX5601-T1, same device just ISP rebranding but with slight difference in Openwrt flashing instructions. flashable and great hardware same as GLINT MT6000 without the emmc and a lot cheaper.
Any of the Cudy devices TR-3000, WR-3000/S/H.
all of these are current favourites for Openwrt.
If you want to experiment and want to test water.
Quantumm Fiber W1700k is Cheap Wifi 7 triband (2.4Ghz, 5Ghz, 6Ghz) AP, but Openwrt is wip.