But it’s important to fit a made-up bridge into a made-up exterior, then stop without thinking about the implications because some things are more made up than others?
There's nothing "showstopping" to the idea of an offset bridge that's implied by these considerations.
Ship classes have unique features not shared by other classes in the real world. Heck, there's individual variation in the real world between ships in the same class.
There's no in-universe technical obstacle to the offset angle.
In the day of TOS, there's no canonical evidence contradicting the offset angle, and afterwards in the TOS films (which went further and canonized the FJ plans, including the offset) and TNG-era, there's still no evidence
of original intent.
As pointed out way upthread now, the "Phase II"
Enterprise explicitly had two structures near the bridge to indicate the two elevator shafts, and they were symmetrically placed [
https://blog.trekcore.com/2018/04/review-eaglemoss-star-trek-phase-ii-uss-enterprise-concept/]. So, not only is there no issue, because of the "Phase II"
Enterprise, there's
bona fide evidence supporting the premise that it was understood that the bridge had to be offset on the TOS starship. Of course, you could also interpret the "Phase II"
Enterprise arrangement as simply an effort to improve the match between interior and exterior, and in that case it would be silent on the issue.
We're just back to "don't know," where we've always been.