I have seen small two bearing alternators(generators) bolted off to the side of the front of the tractor, and ran by fan type belts,
and years ago, 1973 I had bought (still have it) what looked like a generator on a old 6 volt tractor but was wired for 120 ac, and it would mount on the side like a generator and ran by fan belts, it was about 1200 watts, or so,
really a small carry all, or set of forks on the three point and a small 120/240 generator would be easer the majority of the time,
I have a 10,000 watt alternator/220 amp welder, now and thus having power is not an issue but in the past I found putting the old 3500 watt generator on the truck was easer, and normally better than the under the hood unit I had in 1973,
but the pto units are good, there is not another motor to maintain,
but get your transfer switch set up and the hook up cords you need made up and so on before you need them in an emergency, (my BIL did not and wired it up wrong in the cold and blowing snow and ended up blowing out about half of there electrical system and items, (I think the dryer, one of their furnace, some other electronics, and a big tv and other smaller items) so it is good to do it when your not pressured, and in need, and get help if you have doubt,