Problems with 06 P59 and 3 Bar SD OS

Hey guys, just ran into a problem when doing the initial setup on my LS swap.
The Car is a 69 Nova. The engine is a 5.3 L33. The ECU is a P59 with the 12606807 OS. Car has Drive-by-Wire or I would have considered swapping to another ECU.
I'm also wanting to do a 4L60e to 4L80e segment swap.

I noticed that the 3 Bar SD wasn't available when trying to change OS on my car.
If I dig, it looks like the only 2006 truck P59 OS that supports 3 bar map is 12587811.

Would it be possible to reflash to the 12587811 OS and do a 4L80e segment swap without any conflicts? Is there going to be an issue with the DBW?
I guess the next question would be, where could I get the file, and would I need to re-license and use 2 more credits when doing this.

Not new to tuning, just new to the HPTuners interface.

I found a file with the 12587811 OS.
It appears to be for a 6.0 with a 4L80e (my current ECU was setup for a 5.3 with a 4L60e), so I wouldn't have to do the transmission swap.
How do I know if the drive-by-wire will be fully compatible? I think other than that, I shouldn't have any issues.

I take it I will have to re-license this .hpt file, make my changes and then just flash it back to the ECU, and thats it?

Did you ever get this figured out? im dealing with the same issue, my last truck was a 2005 and could do 3bar this one is a 2007 and only 2 bar, I need that boooost!!