I have to disagree with Joestue... which is dangerous, as he knows what he is talking about.
But in this instance, the long salient poles mean that current limiting will occur very early, and as such your current may be as low as 5-8 amps max. It will not increase beyond there regardless of the load impedance..... so if you stick to normal magnetic theory, you will do little better than that.
However, empirical testing shows, that the only way you will do any better is to ignore the steel altogether ( almost). As soon as you saturate, it well be seen by the magnets as air core not iron core .... and so at the expense of magnetic efficiency.... you stack as much neo as you can... It won't take much to saturate it anyway, so forget that, and drive as much flux as humanly possible into the coils.... Thick as you can, as tight as you can... and ignore inter magnet leakage arguments, they are all true, but it is the cost of driving flux down into the coils.... there is no other way.
Even then it is probably only a doubling plus a bit in current that will be attained... air core is not efficient, but works to make the thing more powerful.
Beware, in it's original ferrite guise, you will not burn it out shorted all day, with the neo's stacked in there it will be possible to over heat the thing I suspect
If you rewind then that will be a different matter, but the same logic applies.
A rewind that gives you a lower volt, higher current winding by using more poles for the same voltage, will allow higher currents before the current limit kicks in.
In these motors/alternators, it is the back MMF that will dictate the performance at the top end. When the coil back MMF can get to equilibrium with the magnet MMF, then current limit sets in, and cannot be beaten by rpm or anything else.
If you can let the voltage rise as the current stalls, then your electronic gadgetry will save the day, and you can use Joestue's answer instead, as the current stall is not the end of your power output in the case of a buck converter... let the rpm rise, voltage rises, so power increases.