Why not write your own firmware for these? They may be a lot more sophisticated than I am thinking, but voltage regulators usually have a datasheet/manual with a set of control registers, and you likely want to set those registers based on the physical hardware you have.

The regulators are actually quite sophisticated and have many undocumented registers that set how things like the communications with the processor work, nonlinear control algorithms, etc.

Very interesting. I would assume that parameters for the control algorithms are actually a few of the things you want to set for yourself, since that lets you optimize system stability under load switches. Your board might also have more or less inductance or capacitance than other motherboards, and this can affect the stability and performance of the control loop a lot. It's a shame they don't give you the documentation about those control systems to figure out how to set those parameters for yourself.