I have a 5.3 Severne blade and it rigs beautifully on a 430 (PWX) RDM. It has an adjustable head strap that is easy to adjust. The top does not stick out very much at all.
I have heard Derek Rijff of Windsport magazine say that a 400/430 combo mast is an excellent travel mast (to keep travel weight down). So, it can't be that bad. But, if I had a choice, I would pick one that has the correct bend. I would rig the 430.