I don't know how many people are really using MachFive in surround mode, but other than the obvious libraries, I thought I'd start a list of surround sample libraries, fwiw.
SPL: Surrounded By Drums
http://www.spl-usa.com/DVD2162/dvd2162_e.html
more to come
Surround Sample Collections
Moderator: James Steele
Surround Sample Collections
6,1 MacPro, 96GB RAM, macOS Monterey 12.7.6, DP 11.33