Taming the buck with a Type III compensator

I recently designed and built my first DC/DC converter, a synchronous buck regulating some hefty DC currents. It turned out to work okay-ish (except the overvoltage crowbar), but I had a nagging feeling that it could (and should) be improved further. Even though the prototype made it through a testing regime of load currents (up to the full rated load of 5A) effected via mechanical switches…