I used to work in lingerie dept. once in a while. - a man dressed as man would come in to buy a gift, some wanted assistance, some not. I don’t think they made other women uncomfortable… they were I think, viewed as “an interesting customer” as men not common in that area of shop
Sometimes we would get men, “browsing” with creep vibes. No buying, just looking & looking. Not even touching a hangar.
women the lingerie dept, are generally focused and there for something. Not many ever “browsing”, even if browsing … women would be touching fabric, looking at sizes…
just my observations …
From working w bras, spanks, slips, foundations …. I would assume that a transitioning / trans person would get better fitting garments in a speciality shop or bespoke website.