I’ve been using Prowlarr and Jacket to do mass searches of public trackers and my Usenet sources for every variation of surround, multichannel, dvd-a, bd-a sacd, dff, dsd, atmos, ac3, dts, 5.1, 7.1, etc etc etc…
I think I have about 70 surround albums so far, excluding concerts that I have a separate collection of.