Either way I'm not really thinking about genital development but brain development, if there's some underlying architectural 'XX' and 'XY' structure of the brain and how it expects the body it's piloting to be and if that could misalign with body development. If we start off as a 'blank' template that is later specialised, doesn't really change that concept...
tbh I'm more just thinking of a simplified model that could be used as a starting point to help cis people who are in that "I don't really get trans" category and "you don't need to get it, just accept it" doesn't work get their heads around it as a "thing that can happen".
Been revisiting a Human Behavioral Biology lecture series recently (by one of my favorite researchers in the field), and as of the mid 2010s there's plenty of research pointing to developmental differences between cishet, cis-queer, and trans bodies. And they tend to be complex, and the research is underfunded at best, or a side-effect of research on cis populations more often... but:
Things like how the speed of the inner-ear noise experienced when you plug your ears varies based on what sex you're
attracted to, regardless of your sex. Things like phantom limb sensations for lost bodyparts (genitals, breasts) removed as part of cancer treatment, which are widely reported among cis populations, but nearly never among trans populations, including those who were (at the time) not aware they were trans. And things like "fixed action patterns" (unlearned lizard-brain reflexes) that are hard-coded physiological responses; for those that vary by sex, the bodies of trans populations tend to have the opposite responses, and this is seen before any hormone changes etc, which suggests it's developmental.