The CT LBB2 rule is any A starport can build any TL ship up to TL15 Z drives regardless of world TL.
LBB2: Any ship can be built by any starport type A, TLs be damned.
That’s not how I read LBB2 (well, in fact TTB)…
TTB, page 82:
The technological level is used in conjunction with the technological level table to determine the general quality and capability of local industry.(…) In most cases, such goods are the best which may be produced locally, although better goods may be imported by local organizations or businesses when a specific need is felt.
As Regina is TL 10, the maximum ships it can locally build are those with drives H. Of course it can import larger ones, but one can hardly expect it to be routine…
Of course, the Naval Base may have capacity to repair higher TL ships…
And, in any case, the Kinnunir is clarly a HG design, so HG should apply, if we want narrative and rules to match
But it’s clear this was not a priority for Traveller designers…
And this is one of the reasons I so insist in not repeating those errors if a BSC is ibntended to be developed that should match with narrative (as seems roboject’s intent)