Don’t feel bad. I have yet to encounter a hay farmer that will alter the bale size for a client unless that client is a huge client.
If your main problem is a too short spear that lets the bale tip and slip out of your spear, try adding a pipe sized to fit just right over the spear and maybe 2’ longer, to give you that extra balance on the spear so it doesn’t tip.
If you push a bit, the pipe should spear the bale about like the spear does, as loose as they seem to be packed.
Or get a stout 5’ tamping bar and chain/strap it to the spear in two or three places so it sticks 2’ past it, as an extension of it.
A wonderful farmer is a gift! I understand your choices completely.
I’ve got a similar sized tractor that works just fine at both ends. On the front end loader I sometimes get bales that are right at its limit and can’t stack them two high. I’ll add my vote for shorter top link. Adjust the top link so that dropped to the ground the spear is pointing up a little. Then when you raise it up it should be angled up significantly.
Plus lifting the back of the bale more than the front as the whole bale is lifted adds to the weight on the tractor back axle, giving it a little more oomph! to work with.
Always remember, any time we are stressing a machine close to it’s limits, go veeeery slowly, in the lowest gear, so if something breaks, a hydraulic connection or part of the tractor, stopping will be instantaneous, the wreck won’t be quite as bad.