I have not seen that, though I have seen a few videos of 2 wheel tractors producing hay on steep hillsides in Switzerland I believe.
Myself, I can see a resurgence in loose hay. The biggest issues with it have been largely overcome, and that is with storage and retrieval.
I realize haystacks shed water and that can be done certainly, however with acreage getting smaller, loss would be detrimental on micro or small farms so a storage facility would be best. Years ago building a building was troublesome for a slew of reasons, but today, with fabric barns, cost is greatly reduced and some rather big areas can be covered possibly making loose hay feasible.
The other issue is with retrieval. It sounds silly but anyone who has tried to pitch loose hay from a stack knows how interwoven and difficult this is. But we have this same issue with silage so grapple buckets and silage saws have taken care of that issue.
I just think it is absolutely insane that a good baler today is approaching 30,000 to 40,000 dollars, and even a good used one will set you back $14,000. When I found out a mini 2 foot round baler was available I though that might be the answer, until I saw it carried a $18,000 price tag. Yikes!!
I knew of a neighbor as a kid who put long forks on his tractors loader and after mowing and raking, he scooped up the hay and put it in a big pile and fed his animals all winter from that. He only did 60-80 acres or so, but it worked, and today a new bucket and cheap fabric barn could improve easily on his deficiencies. But silage too. I have sheep which can easily process silage so that is the road I am headed.
There it is! I saw this when I first started researching the possibilities on my steep land. Seems like the OP is in northern England and posted years ago, but I hope you still see this and can benefit from it. Perhaps if you get a chance to go on a trip and have the money you could travel over the creek to Switzerland and learn from the masters.
Anyway, I love those ziplines! And the music and views across the Meadows, the Alpine shacks where they eat summer sausage, bread and cheese for lunch. Probably a beer too (come on, it's Western Europe... They drink beer with breakfast). It's all the things I imagine about Alpine farming. The only thing missing was the guys with the huge horns shouting "Ricola!"
I love a woman who dresses in stainless steel ... and carries tiny ads:
Binge on 17 Seasons of Permaculture Design Monkeys!