Could you unpack that a little? Like, I'm not saying I disagree with any of what you say, but could you just say it over again with more words so I'm sure I understand what goes into this? Because I'm quite happy to establish gender-neutral primogeniture, but I'm not seeing how this is a problem with Laenor.
It's about patrilinearity vs ambilinearity.
1) As I understand it, Viserys' decision was not
just about us, but rather that our heir should also be our firstborn regardless of gender and so on. It would in effect finally establish a true Targaryen order of succession, something that so far hasn't existed and was done rather ad hoc.
2) Now, of course, this would hold true regardless of naming conventions, but the two things do go together. If, hypothetically, we had female succession, but pure patrlinearity, then we'd end up with a lot of dynasty switches, even if it's just name changes.
But moreso than that - patrilinearity would still mark us as somehow less legitimate as a dynast and hence monarch. Like we only got on the throne through an exception, a technicality - but it's still
meant to be male succession, as reflected in the naming conventions.
We'd still not be equal to male rulers in terms of legitimacy that way, and surely that equality in legitimacy has to be our goal - we are the monarch, no exceptions, no differences to a male monarch.
3) So equal primogeniture and ambilinearity need to go together, as a matter of legitimacy if nothing else - as they do in Dorne, in fact, as an example.
4) However, the canon marriage contract with Laenor made all of Rhaenyra's children with him
Velaryons. The eldest would then take on the name Targaryen upon becoming Prince of Dragonstone, but it's still... very murky, I feel like. As I said in point 2, that still smells of making an exception due to circumstances, rather than regular legitimacy in our own right.
Of course, part of it is t hat this names mix-up is necessary because Laenor is heir of Driftmark in his own right, but that is then exactly what stands against him.
5) Thus, a marriage with a non-heir, with a contract clearly stating that our children will be Targaryens (basically in the Dornish fashion without calling it that), would be the best in t his regard. It would set a signal that a woman can pass down both the family name and the right to rule, points that do go hand in hand.
6) Of course, "unfortunately", OTOH, there is much speaking
for Laenor (dragons, mostly) that could justify compromising on this matter in this
specific case. But hence why I said "ideally".