I think that what you are driving it with makes a huge difference in attitude.
My mill will push out 45 amps @55+ volts or more in a gust if the furling is caught the wrong way at the wrong time into batteries trying to stall it.
It may last for only a few seconds until it sorts itself out, but it means that the buck would have to easily absorb that kind of power..... that is a big ask and a big buck.
From a reliability point of view, smaller mills may be ok to keep under control, but mine has seen 5kw before when I let it loose at higher voltages (145V @ A40+ amps), so where do you design for with a buck? what kind of peaks would I expect with this mill? I don't know, but I gave up on it (raw fear) rather than it giving up, It would do more than 5kw if you continued to match the load to it via buck in a big blow.
And don't think that furl will save you, I have 8" offset now, and an overlight tail, starts to furl at only 500w, but if confused will still pull over 30A for a short time before cutting back to 500-1000w in full furl. If I tried to mppt it, you can bet that things would go out of control for short periods... enough to blow things up I suspect.
At least boost has a design max limit.... simple stuff.
...........oztules