I won’t speak to the devices other than to say the wax206 should be well capable. If it’s wifi performance meets your needs now I would delay buying an AP atm. You will need a managed switch if you intend to run Vlans.
I run a fork of openwrt/softlowd monitoring my lan, guest, and IOT networks to Netflow collector modules on my network monitor application on an internal server. I don’t use a network analyzer, but all Netflow collectors will expect the same flows.
I run a WRT1900ACS, a managed switch, and a Unifi AP by way of reference.
I have no issues on the network given my use case. I just monitor my network - making sure everything us up, sending alerts, generating reports . . . for that I set softflowd to use option sampling_rate ‘100’ # sample 1 of 100 packets
In the case where I want to see full details I will set sample rate to 1 only for that interface. Again I see acceptable cpu loads.