I tried the patches on the BDU MACV 5 uniform (Tiger Green IIRC) and they both worked without issue. Except that the load bearing equipment/belts/vests would cover the patches on the uniforms.
Which, given the placement of the patches (over the respective breast pockets on the BDU blouse), and the vest geometry, the options would be to not wear an item in the vest slot or only use vests that do not/minimally cover the front torso.
I'll double check once I'm home to make sure that I am not misremembering something.