I see we're working on achieving the results we want with some of the same techniques.

I have to mention two gripes about the P99rs.
1) The balance adjustment doesn't work on the sub output.
This won't be noticed by anyone with only one sub or possibly with more than one in their trunk/hatch where they're farther away for the listening position.
I will have to disconnect one sub to isolate the other one in order to TA it with any other drivers.
These are directly behind me (extended cab ranger).

2) Why did they put the TA in inches instead of milliseconds?
This makes everything backwards, at least to me it does.
I would rather add delay to the driver closest to me (drivers side), not choose the driver on the opposite side (pass.side) and add inches to it in order to delay the closer one (driver side).

I'm still working on TA between drivers on the same side, I haven't figured out what I should be listening for.