I've been doing this for years, but it's hard work trying to get information on how bad these devices could spy on you - before you buy them
I just guess now and make sure the company has a good returns policy
I just guess now and make sure the company has a good returns policy
The orange flag is when setup requests my wifi password.
But the big red flag for me is when configuration fails without unfettered WAN access. In this case, the product goes back in the box. If you allow this, you allow anything. Someone else effectively owns the device.
An easy test for this --- simply unplug your network from the WAN modem and see what happens.