The John Deere thing isn't so much about the repair, but modify.
Deere sells the same tractor in several different HP levels. More power costs more money. No hardware change, only software. So farmers want the higher HP numbers. The higher HP also make higher emissions levels.
So Deere is fighting a couple of battles here. As the HP goes up, so does the broken parts. Warranty costs. The higher price tag of the higher HP option has a chunk of that money going into the warranty department. Pays for the warranty repairs. The warranty department is funded somehow, that somehow is a share of the new tractor price.
Next up is the corporate emissions limits. They can sell some dirtier tractors so long as they balance that out with cleaner ones. But if the clean ones are being made dirty it throws off the balance and out of compliance.
As for cranking up the HP, I could care less. Expect the warranty to be void. Have you ever seen a farmer buy a new tractor? (Hint, I grew up in Kansas) They expect EVERYTHING to be covered by warranty. Explain to them that the warranty went away because of a performance upgrade. Magnuson Moss act makes that difficult. The manufacturer now how has to prove what you did caused the damage in order to deny a warranty claim. Lets say a transmission main shaft bearing failed. Was that failure going to happen in the warranty period at the lower HP level? How do you deny the warranty claim stating that the part failed from a higher HP level, when you sell that same HP level and use the same part? The higher HP might push the mean service life of the part from 10,000 hours to only 1,000 hours. Thus the higher warranty costs on the new tractor would cover that. But if the farmer didn't put the money into the warranty via the higher cost of the tractor when new, should he still be allowed to get the claim?
If you say yes, why would anyone buy the higher HP and more expensive tractor new? Just reprogram and cheat the system.
So only sell the higher HP tractors? Now they are closing the door on the lower HP users forcing them to pay more for HP they don't need.
Engineer them at different HP levels, R&D is expensive, manufacturing complexity is costly.
The answers are not as cut and dry simple as you would think they are.
