As far as the FEL mounting on a tractor. Any cast iron based tractor.
The long life of the machine is best served with a loader mounting framework that spreads forces along the length of the machine. You reduce the pressure on any one component by spreading the force over a larger area. It is what it is... This is not opinion.
As far as Kris' tractor... Definite block casting flaw, or uneven mounting surface on transmission, or imperfection on some surface somewhere when tightened. (this part IS opinion, but I feel pretty sure). And NH should step up to the plate.
As far as designing something past the point of failure. As far as tractors are concerned, it cannot be done (I admit this part also is opinion) .Because when you were done you would not have a swiss army knife style tractor that we are talking about. The use would be too narrow in the end result, ie forklift, bucket loader, excavator, whatever, -you name it.... But you can design to increase longevity. Which brings up the off shoot discussion on loader mounting techniques.
I still would not hesitate to purchase Kris' repaired tractor and use it with the 7308 loader on it. No problem, good machine and would be VERY happy to have it.
One more note and I will shut up... I have seen major damage, in person, numbers of times through the years, (I wish I had pictures to show you and will keep this in mind for the future). All different makes, all using a loader. From the old machines to the maybe early 90's. That one that I am guessing maybe early 90's I saw about 8 years ago. Co-worker in Palmer Ma, Kubota around 20-25hp, plowing snow in his driveway. Broke the transmission housing where the loader mounted and it was a much more sorrowful sight than Kris' because the tractor could not be moved. I doubted any abuse. And it was repaired. Other units that I have seen I cannot even guess if it was due to the operator. I saw only after the fact. I DO always notice the way the loader is mounted, because I want to know why... CSI tractor

because I don't think it should happen...
One more thing, of the cracked or broken bell housings, front engine mount tabs (most CUT's today do not have these, instead they use the front steel rails, dispersing pressure to a high tensel strength material to a low (block) using the least amount of material), and broken or cracked rear corner engine mounts (including angular engine cracks), This is THE first top to bottom rear engine crack in THIS manner that I have ever seen. Kris, would a prize make you feel better? Well I hope very much for you that it comes from NH in the form of a repair or credit towards a repair.
One of the problems with the net is that you can't pass around a hat for a good cause.
Joe