I have a Linksys Mesh and am looking at getting a CAX80

AP mode means all router and most features on the MESH system would be disabled. Leaving the wifi system running and maybe some other basic features. 

Something to check with the Mfr about for support and information regarding there product. 

IF you want to run any kind of MESH system with the CAX80, this can be done. A couple of options, disable the CAX80s wifi radio, use the CAX80 in router mode, connect up a MESH system in AP mode. You can connect up a MESH system in router mode as well and use the CAX80 DMZ to avoid double NAT issues. 

Or you can configure the CAX80 for modem only mode, then use any MESH system in router mode.