Has anyone found a working solution to this scenario? Despite a lot of research, I have not been able to find any eARC capable HDMI switches on the market. The closest I found is this which does support ARC (as opposed to eARC). Not perfect but it might at least allow us to get compressed 5.1 and stereo audio from an LG TV back to the theatre, e.g. for OTA TV.
Alternatively, if ARC is not possible in any meaningful way, has anyone found a (non-ARC) matrix switch that could be integrated with BLI+BR1?