You can't buy a hackable, open-platform tractor. What are you doing while waiting for this very hypothical tractor ? You stop working ?
Why are people buying these annoying tractors anyway? The reason to me seems: They are worth the trouble.
Here's the thing. They should be able to lease equipment with restrictions. However, if you're going to call it a sale, then I don't see why they should have the right to restrict your ability to modify it. A sale implies a change of ownership. If they can restrict what you can do with the product after you bought it, then there wasn't really a change of ownership, was there?
I guess you haven't seen John Deere tractors in a while.
As huge a gulf in technology as that may be, retracing over ground that has already been surveyed once is much easier than blazing a trail through wilderness. It only takes 50 years to advance that far in technology the first time you try it. The second time around, it goes much faster and less expensively, especially for everything with lapsed patent protection.
That particular tractor is supposed to be a bootstrapping device, so that in the unlikely circumstance that we do lose the benefit of modern infrastructure, it can mostly be rebuilt before anybody forgets how or why.
With the benefit of the modern manufacturing infrastructure, anyone else could copy a 1995 model of Deere tractor and just leave off the trademark elements.
The LifeTrac is designed around the resources that a self-sustaining OSE community could likely produce or scavenge. It's basically what two people and a rudimentary machine shop could build in a reasonable period of time.
Again, given the run-up in prices for used, owner-repairable tractors, there may be a market for copying the most popular models for new manufacture, and leaving out anything still patented or trademarked. Serious farmers won't build their own LifeTrac unless it is impossible to get a factory-built tractor.