OK. Satisfication Update!
Previous setups:
V1: LG B6 > LG Sound Sync > Optical cable > SJ9 = Controllable via LG TV remote control but ONLY outputting PCM therefor very shallow soundstage and no 5.1 rear signals passed to LG H3 rear surrounds = Unsatisfied Ed.
V2: LG B6 > Optical > Optical cable > SJ9 = Not controllable via LG TV remote control but outputting Dolby signal therefor wide soundstage and discreet 5.1 signals being sent to LG H3 rear surrounds = Still Unsatisfied Ed
V3: LG B6 > HDMI ARC > HDMI High Speed cable > SJ9 = Controllable via LG TV remore control AND outputting Dolby signal AND a MUCH wider soundstage from just the soundbar AND discreet 5.1 signals being sent to the LG H3 rear surrounds =
VERY happy Ed!
The problem I had was that I had a very specific set of requirements from this soundbar and for a while I didn't think it would be able to tick ALL my boxes. The only thing it still does that's suboptimal is that it shares the sound from things like OTA broadcast TV and the Spotify app equally over the soundbar and the rear surrounds. If there was a way to enable an automatic switch to discern whether a singal was 5.1 or not and output the appropriate signal to the surrounds then everything I want would be GOLD!
Worth reiterating how much better the soundstage is over HDMI. I just watched the scene in Avatar where Jake spends his first night on Pandora and WOWOWOWOW! I seriously thought I had the rear surrounds on. Fantastic!
Sorry for being a bit of a killjoy folks. I just worked myself up into a worry as I'd been looking forward to this soundbar since it was announced. I'm looking forward to sharing this with my girlfrield later as she went to work today with me sitting in front of the TV scratching my head.