Always found it frustrating that I can't wear my favourite hat with armor that requires a helmet
So, why not allow two types of head protection, facemask or helmet where only the helmet is currently available? This could even just be done as an 'upgrade' mission which doesn't change the stats, just the type.
PS I bought goggles so that I could keep my hat on when using Viceroy
PPS I really like keeping my hat on