Isn't this the problem with warranties? People could try to mod it, end up damaging it and try to get it replaced with warranties.
I also don't fully understand this software. Is it just completely vendor locked? That sounds really unreasonable. It should allow for at least basic debugging and trouble shooting.
Is this software locking only in large $100k + harvester type equipment? Does the vendor have other reasonable explanation of doing this?
I wonder if the software designer for this equipments would have reasonable arguments for such locks or if this is just profit driven decision.