I live in a hot and humid area and need a way to help stabilize Swiss Meringue Buttercream.  Would gelatin work?  If so does anyone know a good ratio of gelatin to add to the buttercream? (or recipe)

wouldn't the butter still melt?

keeping it cold throughout the delivery will stabilize it

Agree with K8memphis on this one. I make swiss meringue all the time. I have researched and researched but to no avail. I come to accept there is nothing to stabilize it other than keeping it cool. It is the way it is made. I would think if you put gelatin in it, then it is no longer SMBC.