creativehum
SOC-14 1K
There's nothing about a starport having a tech level different from that of a world (this fact is confirmed in LBB5).
Thus, the world TL governs the ships produced at the starports.
There is nothing on Book 3 about the world and the starport being connected either. The quote you pulled could easily refer to the world (things produced on a world) and have nothing to do with the starport.
As for Book 5 -- it's its own thing -- to be used or not used as the Referee wishes. (I don't think some people understand that for a lot of folks back in the '80s Traveller was Books 1-3 and the other products in the game line were things "out there" that they never really looked at.)
Book 5 creates a rule that does not exist in Book 3 --which is fine. But to say because something is in Book 5 one must read Book 3 a certain way is to blow past the clearly modular nature of the Classic Traveller line. (Clear to me. I understand there are plenty of people who don't see the matter this way.)
The overall point I'm after -- if someone were playing with only Books 1-3 -- as the game was originally built to be played -- there is no reason to assume the Referee would be making the same assumptions you are making. I'm not saying you are wrong for setting these rules for your setting. I'm saying that trying to nail this down for everyone is an unneeded overreach.