The Osram Olson SSL-80, with its 80° emitting angle is the most efficient LED for TIR optics. Even though it’s such a narrow beam it still uses a dome so it suffers less optical losses than a XP-L HI or other dedomed emitter would [in the same optic] giving it the highest cd per lm of any led when used with a TIR, even beating the throw king flat white 1mm2.

Its a 3030 so it is possible to reflow them on XP triple boards (tricky but doable) or I believe LED4Power has a carclo compatible 3030 triple mcpcb if you prefer.

You can get decent throw with more common emitters too but you said best…