Hi @P Diddy
Thanks for your post!
No - the lossless stream would only be played to the Beam and the Fives would receive a compressed version. They would also likely be out-of-sync with the Beam, as for network play the audio must be buffered for reliable playback, and the Beam will not wait for this so that synchronisation with the TV’s picture can be maintained.
I would instead recommend downloading lossless ALAC (like FLAC but by Apple) files from Apple Music to be stored locally in a network-accessible location, and pointing Sonos’ Music Library to that location. This way, all players can buffer the audio and synchronise playback together.
Add your music library to Sonos
I hope this helps.