As Rob says, test transmissions are notoriously promising. Someone said, with apparent authority, that Tom Anderson had to balance seemingly irreconcilable behind the scenes views that day. And the BBC poached him later.
the specials would be impossible to run permanently because most of the folks wouldn’t be available to keep it going - voluntarily. the streaming numbers will link to a range of other factors - not least the Caroline brand/following and terrestrial coverage. It would be like comparing Radio 1 Dance, Relax and the main channel and concluding to stick with the latter and turn the others off.
Perhaps those specials are just a bit more special for their rarity. entertainment is subjective. Yes there’s been great talent in the past, and perhaps more magic, whatever that is defined as (being an outlaw perhaps), but as with music to dismiss it as never repeatable is frankly what some always will say. A younger person observed, the brand is powerful and could succeed in more music styles - not less