I wasn't expecting to get into a full discussion of various suppliers' prices for bundled and unbundled lines and broadband . The discussion started with the Plusnet price rises, and the question of Caller Display charges which are being banned.
However, yes, the Pulse8 £6 line rental applies on TTB MPF connections. Pulse8 line rental only is straight WLR3 via Pulse8 and Openreach, not involving TTB at all.
They have also been offering this at the current prices for several years. Your suggested Uno possibility has only recently become available. Note also that Uno prices (for everything) do not include Vat.