With all due respect, I have my own doubts if all the secondary speakers pair to the Single Primary Flare 2.
Linux Tech Tips showed the video with Flare 2 spread across his home, and mentioned the audio was pretty clear, the main Primary speaker was in his living room (i think so, that is where he started all the main pairing)
The Bluetooth range should be tremendous to get that kind of an audio output, paried to 99 other speakers from a single Primary Flare 2… it still uses BT 5.0 , and has a range of 66 ft / 20 meters
But if this is really the case – then why not Soundcore create a sort of a Bluetooth Router (my idea back from September) which acts as a BT transmitter to connect to more 99 devices simultaneously, which helps connect multiple speakers to form a cluster of speakers,