There are no [multiple] modulation schemes on anything but 802.11, and I've noted WiFi's not the primary user. You go on to disagree:
Inaccurate again; and most of your statements are opinion. Last I checked, most people have WiFi, Bluetooth and microwaves, though. I've also seen 2 microwaves, one interferes, one doesn't (different frequencies and/or harmonic leakage). So, no debate here. I'll just agree with @lantis1008 -
Inaccurate again. My device uses 40MHz all the time...when the band isn't congested. I do not have to force 40MHz for this to occur. I simply switch to 40MHz, and when needed (and the band's free), it switches.
This is illegal in most cases; and the manufacturer is in violation. Search this community's threads. I (and others) describe why.
I'll be proposing that this thread be closed if we continue into illegal interferance, as the community rules don't support discussion of any other illegal thing. Causing electronic interference is illegal in most countries. We already have a lot of problems with devices because of the fear of malicious actors with 3rd party software...with a lack of knowledge of the Communications Act.