Hey, Luke. I don't know if I'm still your friend, but I'm not angered, and I'll bite --- plenty of people I know have tried this. Joining the military is common, although I have no idea if this is to effect hypermasculinity or not (most of my trans friends are dmab.) Janae Marie Kroc is probably the most extreme example I can name, but I expect if you find a forum for exmilitary trans folk somewhere you'll be able to find a lot more data on this.
I think I could argue that in the years I knew you personally (like 2015 to 2017) I was trying to do this in some kind of way. LK was one of the first people I publicly floated my name to --- we were out running around campus, I don't know if you were still dating at the time. I have absolutely no idea if either of you care. N=1.
They are, consciously or not, trying to hide in the closet. This is not the worst idea anyone's ever had, especially in a hostile environment.
I appreciate that you're still working in an environment I gave up on ever making progress in. I just...wasn't equal to it. I hope you're well.
"Chemical cisgenderization" is usually just called "detransition." To do it, you stop taking hormones. Unless you've had the appropriate surgeries (which most of us haven't because it's very expensive) your body will do it by itself.
Transfeminine HRT consists of synthetic estrogen and an anti-androgen of some sort (usually spironolactone or finasteride.) Estrogen monotherapy, in higher doses, is coming more into vogue now that more has been published that suggests it's more effective.
Anyway, I know some people who have tried. I'm told the dysphoria comes right back, worse than ever. I know at least one (AMAB nonbinary) person who actually needed to take low-dose T after their orchiectomy, although the dose was an order of magnitude less than what their body naturally produced, but that's rather an exceptional case.
Actual desistance rates are on the order of a few percent*, and >90% of those are for reasons other than "I'm not actually trans." [0]
[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8213007/