Prevent auto downshifting while Jake braking

How to disable automatic transmission downshifting with engine brake activated? I set it to Perform mode but it still goes down at the moment I expect it the least.

P.s also, aside from Jake brake but going up hill, it skips eleventh gear to tenth causing needless over rev oftentimes. Is it just mine issue or do other ultra shift owners have this, too?

 

Yes, I have the same trans. How do you enable manual mode? Pressing the button on the lever switches it from Economy to Perform but just for a short period of time. Switching to manual should solve the issue, I guess. At least while going downhill

 

NVM I found it, long press on the same button enables manual mode. A completely different story now.

 

A) you can lose control of the truck in a curve or when it is slippery. Besides, it accelerates even more while downshifting, sometimes absolutely no need to do this
B) In most cases I'm ok with the third stage on without needing it to downshift even more
C) Stay focused on the road and not on the engine revving, speed going up any other unnecessary changes I am not expecting to happen