I was guessing how you had them connected. I said Android because I couldn't find an iPad with a resolution of 1432x1074. Probably Duet just uses a scaled mode on the iPad.
People have shown 6 display setups on the original M1 Macs before (I think there's a thread on MacRumors that mentions it and a YouTube video). In that case, a setup with 7 displays would be interesting.