My best bet would be a sports bra! I would use one used in women's sports thats supposed to hold back bigger ch3sts, which is a high support one. But, PLEASE treat it like a normal binder. Don't use it for too long, and even though it's used in sports, try not to do too many straining things in it. I used one (which give or take was too small for me, which was intended) and it messed me up for a while where my ribs constantly hurt and breathing was awful for a bit. Just be careful, and use the bra + hoodies or something like tcking your shirt in and having it billow over edge! It leaves more room for the front and flattens everythin out. (I dunno what your ID entirely is but I'm enby and can wear about anything, and if thats the same for you there's a lot of ways to manipulate clothing to make it flatten you out more!) Best of luck, stay safe!
As someone who struggles with a female body as an enby, I’d say a sports bra that makes you look flatter, I’d say one without padding. But please don’t wear one that restricts breath. Please don’t wear it for too long either good luck
