I just purchased a BE550 router.  I would like to use it with my Linksys MR7500 router.  What would be the ideal way to set up the BE550? AP mode? I'm in a small apartment & trying to extend the wifi signal in the living room. Currently my set up is Linksys MR7500 router as parent node & 1 Linksys MX2001 mesh unit as the child node in the living room. 

I get lots of interference from the condo that's 2 streets away from me that has cell phone antennas on the roof top.

Thanks in advance. I appreciate it.