Brushing gel coat no promlemo since the beginning of time in the boat business, there has been more gel coat brushed on than you can believe, just use a decent brush and brush from the dry area to the wet (like a good varnish job)
Going without gel coat will expose you to a myriad of problems starting with pin holing and ending with a mold surface that is hard to lay-up on; you see the gel coat softens the surface by rounding the corners a little enabling a more easily attainable void free laminate
I will see if there is a brushing Gel coat available here, Overseas it is the norm. The thix index of spray is much less than brush, Viscosity I meant.
But again there is the weight penalty of gel coat on the part