This is yet another "add surround" suggestion, but this time with UI suggestion as well.
Two Busses, Surr Rev and LFE Lowpass are surround bus, takes surround audio as an input. The current channel, "Test Inst." is stereo channel but outputs surround via Surround Panner. Surround Panner is directly accessible in the channel strip, replacing normal pan slider. Surround panner takes a few options, one of which is "Speaker Placement and Panning Law", which is a projects' setting. Here 5.1 ITU speaker placement and -3 dB of panning law is configured. There's 5 dots around the surround panner, they shows speaker placement according to the surround setup (5.1 ITU, 7.1 Dolby, 7.1 SDDS, etc. look them up, they're all different!). Since this is a stereo channel, VU metre should show 6 bars for surround output (I just forgot to draw). Surround panner is showing 2 dots, it's also because it's stereo channel. You should be able to change their degrees of separation.
To correspond this, Audio IO Setup's Outputs tab should have a button named "Add ({0})" where '{0}' is the projects' configuration as String (e.g. 5.1 Surround, 6.1 Surround, 7.1 Surround, Atmos 5.1.2, etc. etc.)
This suggestion assumes planar speaker setup (== no height channels), but if the output surround format does have height channels (e.g. Atmos, Auro 3D), spherical panning should be used (now it's becoming too closer to Logic Pro X...), perhaps you can just drop support for these and concentrate on 5.1/7.1 panning.
Suggested panning laws to be implemented: -3 dB (default), equal-power, -4.5 dB, -6 dB.
