If you put the 15 amp in there and it blows, then you have a problem you need to fix. Better for the fuse to blow than you riding a fireball!
I replaced the fuse block on the 750. Is was melted behind it and so were many of the wires. I replaced the harness at the same time too.
So, in short, yes, put the 15 amp in and see what happens. Keep the other 15 amp where you can get it if needed.