[Skyhigh]

xHP offers, apart from slightly faster shifts, a wide range of customisation settings. Those can be handy irrespective of any engine tuning. I had xHP before any tuning on the engine. There is no link there really, apart from the removal of torque limiters on the gearbox, which is considered essential for a tuned engine, although most tuning platforms now have a way to "cheat" around them. (I personally prefer removing them, as then the correct torque also gets reported... you have seen the opposite in your logs)

Your observation cannot be due to engine tuning, but is a good example of something you can influence with xHP - change the shifting points as you see fit. I have actually done the opposite in D - lowered the shifting points a bit for fuel economy. Especially with a tuned engine, I feel there is enough torque down low to not need high RPMs. For sporty driving - there is S. But everyone is different, hence the customisation possibilities of xHP.