Like yourself, I have found Martin King very generous with his help and advice, and followed his website and debates on the various forums. He often mentioned that reflex boxes would morph into TL's as the length increased! With ML TQWT's he adviced me to use the ported box worksheet to finalise the design as the port position could be accounted for.
So you both seem to be coming from the same direction. Good to know that clever minds can think alike.
As I mentioned in my previous message do you have any frequency impedance charts available for the "2"