I think that having the long hay be 1/4 of the ration would be pushing it. I would try to get a demo first to make sure it would work. 1/10th would be no problem, whether 1/4 will work will depend on how tough and stringy your hay is. It will have a better chance of working if all the knives on the augers are full size and sharp.

Check the tub for wear, ours wear first right by the discharge.

Never, ever put the hay in on the other side. I have had help do that 2x, one time it even bent the main center tube on the reel. The mixer we have now has one bar bent from dropping a slab of hay in the wrong side. Doesn't seem to affect function, but I bet it will affect trade value.