No, this could be made to work actually.
How we got the local government to cooperate in hiding our Enclave / Dig-site? Just
standard Mechanicus bribery, definitely not giving them access to the knowledge and technology so that they can replicate them.
In which case, we do not
probably immediately lose the base and the industrial capacity to all the Mechanicus Enclaves trying to nuke us. But some of them might try sabotage, or "deniable" missile strikes in the immediate confusion. Or just decide to throw subtlety away, and try to take the "dig-site" from us with force. So yes, I'm going to be advocating stealth/underground defences. Maybe not immediately, but at some point definitely.
Because as long as they believe in the fiction of even a
potential STC-fragment, that will tie their hands when it comes to WMDs. So more attention potentially if we are forced to reveal our location, with the possibility of having to defend our base. But less worries about getting nuked back to what we have underground at our ship.
Speaking of which,
@Neablis? What would bunker cost us in RP for designing such a thing? How good we can manage with cost-efficiency in mind?