Favorite warm weather binders/chest reduction hacks?

I've tried a bunch of binders over the years, and my current favorite is a gc2b tank binder, but it's a little clammy in hot weather. I've mostly been getting by with cotton sports bras at a band size two inches smaller than my actual size, with a square-cut, loose overshirt to disguise the lumpiness. That's good enough for a quick trip to the store, but I think have an excuse to buy a new one. (Never mind the... uh... several others in my closet, lol). Any recommendations?