In theory, they are supposed to help. However, I experience with a lot of other legacy IoT devices they don’t play nicely with those settings enabled. In fact, Merlin specifically mentioned to disable those settings on the 2.4GHz band. None of my IoT devices support MU-MIMO anyways. On SNBForums, it is generally recommended to disable those settings now especially on my RT-AC86U. I don’t know what is the situation for other routers.
You can definitely put Wyze into the Guest Network. For routers on the older Merlin 386 firmware, it is ideal to put it in Guest Network 2 or 3 because Guest Network 1 doesn’t abide by the local NTP server and intercepting NTP client requests setting which I mentioned earlier. I believe this was eventually fixed for ASUS WiFi 6 routers with Merlin-Asuswrt firmware 388.1.