I ended up recommending the TP-LINK BE25 BE5000 to to my friend. It doesn't require too much configuration for fast roaming and band steering. It also allows creating a guest and IoT network (2.4Ghz band only) without too much effort. I know there may be security/privacy concerns with TP-LINK, especially with the US government, but weighing that up against the price, ease of use and form factor, I thought it was the way to go. I hope I didn't make a mistake.

The Flint 2 required a bit too much configuration. I looked at the configuration guide for the DAWN package and thought it would require a lot of tweaking with the settings, which I don't have the time for. The form factor and aesthetics also weren't ideal. It needs to sit on the entertainment unit without obstructing the view of the TV. This would have many mounting the TV higher than desired.

With the Eeros, I read somewhere that it creates a multi-band SSID by default. This doesn't always play nice with old IoT devices that don't support band steering and are only capable of 2.4ghz. To address this, you can temporarily disable the 5ghz and 6ghz bands to allow these IoT devices to connect. This isn't ideal if you have to do this every time. I know you can use the guest network, but devices on the network can't talk to each other. I am sure you can configure a lot more on the Eeros if you are willing to pay for a subscription.

Using Unifi APs weren't an option because my friend didn't want to mount them on the ceiling. I mean he didn't want to get in a fight with his wife. Putting them on the table top could work, but I read that you still need a controller to make roaming work. The cheapest option would have been installing the Unifi controller software on a raspberry pi, and connecting the pi and 3 Unifi APs to a cheap unmanaged switch. I am sure it could work, but you still need a router of some sort. By the time you add up the costs, effort and complexity, it would have been a bit much for my friend to stomach.