Need a switch for a downdraft table......

I’ve been on the lookout for a blower myself for an air cleaner for the ceiling, they are expensive new so grats on finding one.

Hopefully an HVAC pro will catch this so the question can be answered properly. I’m not a pro but as far I know the fan speeds are controlled with the multi color wired harness hooked to the control board, as to whether full voltage is running through those wires I don’t know, and I don’t know if the colors are standardized at to what speeds are being called for. I have the manual for my current furnace if I ever use that one, but manuals for most are online. A simple solution I might try is a two gang box with two to four switches, allowing you to experiment with wiring the harness individually to the switches and then labeling them as to what general speeds they are. I would most likely be satisfied with just two speeds, the lowest for quieter constant recirc, and high to scrub the room. I wouldn’t think there would be much need for more on a downdraft either, I would want it sucking full force when I was sanding, and low to keep the general dust down when I was just fiddling around on other stuff. I could be wrong but rheostat type dimmer switch may be hard to find burly enough to handle those amps, maybe a router speed control?