Hello, I'm Chris.
I will do my best to answer your question fast and accurate using the info you have provided. Thanks for visiting Just Answer.

I know this is far from what your wanting to hear but I will go ahead and tell you since no one else appears to want to engage this post, since its likely not what your looking for.

1. This is a new engine and its electronically controlled, however no one including kubota offers a chip or programmer to boost HP.
2. The reason for this is because kubota has installed blocks in the computer so aftermarket companies cant gain access.
3. Also kubota designed the tractor for said HP and once it is increased wear will occur to all of the power and drivetrain.
4. It is setup currently to make all it can and not damage itself nor create high emissions.
5. Some would think its as simple as just turning up the fuel or adjusting the timing but all thats going to do is add more fuel which will result in higher temperatures as well as more exhaust soot to cause emissions issues as well as carbon up the turbo.
6. So to answer the questions there are no tweaks or programmers you can add to increase the PTO power on the largest tractor and engine kubota makes.

However there are a few things you can do to gain some more HP. Remove the mechanical fan and mount an electric one which will free up about 5 HP. Go with a larger diameter free flowing exhaust from the turbo out which will get another 2-3 HP. Add a propane injector into the intake system which will gain about 15-20 HP. Be aware that most of these changes will void all of the warranty on your tractor. The only thing warrantable will be the cab and electronics and paint all of the powertrain and drivetrain will be void, they will say it was caused by the increased power over there set specs.