Hi, I think @gynemimesis on twitter (x) has been doing surveys including variables like hypermobility. I'd also like to recommend some of my own work. My surveys haven't exactly touched on all of these things you mention, but you might find this one interesting.

Dissecting Gender Dysphoria: Personal Theories & Narratives of MtF Transsexuals (Substack)

This is a write-up for an online convenience survey (sourcing mostly from twitter and reddit, n=72) I put out with two main goals: 

The first goal was to see how trans people responded to a questionnaire consisting of a very broad net of potential components of dysphoria/incongruence (e.g. "I was distressed by the gendered ways people treated me" or "I was aroused by the thought of being the opposite sex" etc.). Then I used Exploratory Factor Analysis to uncover potential themes. The theme I uncovered that seems most relevant to the theory in this article is one I dubbed Gender-Perception Dysphoria:

Factor Summary: This Factor seems to be characterized by concern over what gender one is perceived as. The highest loaded item is explicitly about a tendency to see oneself through a self-conscious lens. The 2nd and 3rd Items are about aspects of appearance most related to social presentation. (as opposed to —for example— concerns about private anatomy)

and maybe to a lesser extent Gender-Attraction Dysphoria

Factor Summary: This Factor seems to be characterized by concern about sex-based appraisal. The kind of appraisal that makes you insecure at least, and maybe specifically appraisal related to mate-value (i.e. people’s attraction to you)

The second goal was to get some qualitative responses to two questions. The first asked subjects to describe their childhood gender non-conformity (or lack thereof), after referencing Anne Lawrence's claim that AGP-Transsexuals exaggerate their childhood femininity or interpret mundane deviations as more extraordinary. The second asked subjects to explain why they think they are trans. What caused it.

The first part of this Substack article covers the qualitative aspects of the study. The second part covers the quantitative aspects

Hi, I really liked this article. The ideas you're developing here ring some bells for me personally and are very similar to a theory of transsexuality I'm developing based my own experiences and grounded in Early Maladaptive Schema (EMS) Theory. I'd like to write a sort of response to this article, recontextualizing this theory as potentially a special case of a broader EMS-Transsexualism framework, I hope that's okay