Additionally, we (and all sessions in the country) can now have as many musicians playing as we like - we're no longer limited to individuals or pairs only. This has freed us to perform as groups.

It has not 'freed' all sessions - only those sessions fortunate enough to be in premises where the licensee has applied and obtained entertainment permisson from a third party.

It certainly does not appear to have freed them in my local where the application for entertainment permission was limited to two performers or less.

But the real question is - if the session could will and often does take place in the complete absence of any audience or spectators for the enjoyment of its participants - why should it be considered to be a licensable Regulated Entertainment in the first place?

Is your local licensing authority insisting on entertainment permission for social games of darts or pool? If not - why not? For these Indoor Sports are now equally considered as much Regulated Entertainment as live music is.