The Mikrotik wAP RBwAP2nD currently has support for 19.07.10. I see from https://openwrt.org/toh/hwdata/mikrotik/mikrotik_rbwap2nd_wap snapshot is available and some activity on this page
On a side note, I have accidentally, but successfully used the wAP R image on this device [21.02.3]
Is there likely to be a 21 or 22 official supported release for this device?
thank you