Due to Turner syndrome presenting as female with only 1 X and no Y a strong case could be made for males typically having a functional female blueprint since they have a single X. Combined with the limb/organ regrowth mechanic and some internal function that let you activate/deactivate genes an XY could regeneratively develop both male and female traits in a pretty believeable scifi way either by having a way to naturally kill off certain tissues or by intentionally damaging them couldn't it?
Yeah if you wanted to angle for that you’d have to take the tissue out and kind start over from stem cells to get the gonad tissue you aim for. though that would of course upset the hormone system something pretty heavy. There’s a reason why HRT is dosed the way it is, and I’m not sure a ‘hard reset’ via tissue damage and regrowth as something else wouldn’t fuck you over pretty hard in some essential body functions, like bone density, since in the meantime you’d be stuck without a functional supply of sex hormones and those are actually pretty damn important. See also: health risks after excision of the gonads in your standard human, say due to cancer. So I’m not sure how good an idea it would be without having some backup system in place.
With a backup system (internal or external) it could work, though of course the switch in hormones would likely create changes like HRT with similar drawbacks re:reversability, though I suppose if you extend the regenerative abilities they’re fixable easier since you can always go full ‘remove everything’.
And of course it’d still be slow.
Edit: i just checked back on Turner syndrome again and apparently the gonads there end up non-functional wrt both procreation and basic hormone production so even a XY base with switching ability wouldn’t result in a ‘functional’ female phenotype.