This is what I do for a variety of different things:

  - $CORP devices are on a VLAN + Wifi that has access to the internet, but no other internal networks
  - Internal network for file servers/printers and the like
  - Personal device network, think laptops/phones/tablets that are mine, can reach internal network
  - IoT network - Think sensors/robot vacuums/"smart devices"
  - Guest network, for well visitors to my home
  - AirPlay network, has all my Apple devices on it to allow for music to be airplay'ed to TV's/HomePods, can be reached from internal/personal/guest network

Now I also understand that I am outlier, I am running a fully segmented, firewall, traffic inspected/logged home network with small business or even large business network gear, with FreeBSD as the router/firewall with a managed switch/WAP platform from TP-Link.

This is not something the average home user or consultant is going to setup/configure/manage and I don't expect it either.

The worry that the $CORP device will be abused to "validate the security of the network its connected to" is very much a possibility. Most corporations have no desire to do so, and endpoint protection is their primary goal, and they don't need to scan your home network to do so, it is all local to the device. It's about protecting the integrity of the device, not the rest of the network around it.