Follow up question: Do you know if the same applies if the WIFI 7 is in Access point mode? And doy ou know if TP-link will sell models with 2.4GHz as well as Wifi 7? The reason I am asking htese...

This is a general question. I know Deco units can be combined and that "the best" model should act as the main router. I have 2 M4 units now. What happens if I add a 6E or 7 router as a main router...