I cannot think of a normal reason to have this UI feature: “Active Spatial Streams: Choose active spatial stream if Auto, 1 or 2 streams.” Just about any user would keep this setting on 2. BTW, what does “Auto” do?
The only reason to switch to 1 spatial stream would be to check and test if one of the two chains is broken - but for that I would need to have a way to select each chain.
This configuration feature can be removed from the web UI.