I think I found the right balance for me by combining a BSM and a Core.
(1) the Core and BSM are covering each other in case of failure, hardware or software, as I would not live without music.
(2) The Core is linked to the BSM (tks MM) and the Core is connected to a TR1 to stream wireless to my BLs
(3) For vinyle sessions, I have a turntable connected to the BSM which is showing its wood face. I just place the record on the turntable, play it and control the volume via the BSM et voilà. Nice look and feel.
(4) When I want to play my music randomly form my digital sources and according to my mood, I use the BSM MW or PP
(5) When I want to listen to my large DLNA collection, Deezer or TuneIn, or to join another B&O Multiroom experience, I use either the BSM/Tablet or App or the Core/App
(6) When I want to use PLEX features to play my DLNA collection, I either use PLEX app on my Samsung TV connected to the Core ,or PLEX web/mobile apps to stream to B&O individual or group Cast products
(7) When I want some kind of voice control (I'm not a big fan of that), I ask Google assistant to play a particular radio station on a given product or cast group
I must admit that wife is lost with all these possibilities, but she only really cares about controlling the TV sound which the Essence remote connected to the Core does perfectly, including jumping from source to source by a simple press, so I can watch TV and enjoy Music at the same time if needed.
To summarize .... the BSM is really nice but has its gaps that a Core can fill easily while providing some redundancy in the backup point of view.