Not flacking for BM, but not really rigorous enough:

a) As we all know, GPU and ASIC miners heat up a room, warm up any stands they are on. So anything in the room warms up.

b) In the video, some if not all miners are sitting on cardboard boxes. You would need to eliminate the cardboard boxes (i believe glue is used in their construction), any manufactured wood product (plywood, cheap shelving) that uses some sort of glue as a binder. Any cheap packs or bags that are made out of polyester. Any construction materials used in building the room.

(Wasn't there an issue with imported drywall a few years back?)

Bottom line, I would expect there are other material candidates in the room that outgas formaldehyde when warmed up.

The possible A3 components would be the heat sink sticky tape and maybe the electrolytic capacitors(they have a small port for possible venting).

I forget, also the packing foam used in shipping the miners would be suspect.