I just joined the mercs boards recently, so don't take my word for it, because I haven't done a lot of reading over there, but I recall a Mando telling me that craft foam (event when coated with a sealer like Mod Podge and painted) is not acceptable for making armor... or no one with armor made of foam will be accepted as a member over there. If I'm remembering it correctly, it was during a conversation about xrobots Youtube tutorial for coating foam armor with slush-casting resin... which might be acceptable, but is very time consuming and gets expensive. Again, I might be wrong because I haven't found it explicitly mentioned over on the mercs forums, but I do trust the friend who told me that.
Aside from that, you've done a great job painting that helmet. I have said in other threads, that I wouldn't make a mando with green armor because with any color armor, someone is going to call you Boba Fett. Green armor makes it harder to correct them!