I think I also saw this post. Yeah, I'm really not sure, myself. The only reason I haven't put a pi box with ST in the living room is this aspect.
I know multichannel loudness processors exist, but they're crazy expensive (to me). There are hardware appliances from Telos Alliance (the manufacturers of the STX unit) shown in this link (
https://success.telosalliance.com/on-air-tv-processing). I know the Linear Acoustic AERO.8000 is by Leif Claesson, who made the Omnia.9 and BreakawayOne software, and his algorithms are solid.
It would be nice if ST had a multichannel edition. If I'm not mistaken, Stereo Tool used to be Radio Tool, so things can evolve IMO.