Well heres as good as any place, but for those delving into tuning here are some mechanical limitations I have found that you should keep in mind with your tuning.
The ECM is only capable of calculating and commanding 80MM3 of fuel in stock form. As I underestand it there is a modifier inside the ECM that can be tweaked that essentially acts like the #9 resistor(although the #9 resistor will give an extra 4MM3 of fuel over a pump that is calibrated and requires a #5) only slightly higher. The accepted max seems to be around 92MM3 of fuel at 3K RPM's from what I could search, but have nothing to verify this. Getting to the 92MM3 of fuel via strictly ECM tuning will take some creative work and finding all of the multipliers to do so.
The DS4 injection pump has a mechanical limit of 22 degrees of timing advance/retard at the pump cam ring. So getting the TDCO as close to -1.94 is rather important so you can allow the pump to reach max timing.
The stock boost pressure sensor is a 2 bar unit meaning it can only read to roughly 29PSI absolute(atmospheric + boost gives you absolute). So if you are at sea level atmospheric pressure is roughly 14.7PSI, this is why you will see 14-15 PSI of boost at idle. Calling for boost numbers beyond the mechanical limits will simply cause the ECM to command max boost regardless which could mean 20+ PSI of boost at sea level as anything over 14.7 above atmospheric it cannot register and it will hold the wastegate actuator fully closed no matter what. And inline resistor mods should not be used with custom tuning as you can now set the values to be what the resistor was making them to before. Heres a calculator I have been using to convert KPA to PSI as the ECM code calls for killipascals
http://www.csgnetwork.com/presskpapsicvt.html . It would be nice to find a table in the ECM to reference boost sensor volts to pressure as this would make the changeover to a 3 bar MAP MUCH easier and allow for boost control of the HX40 via the stock boost system for MAXIMUM control(I know I'm in the minority that actually likes the stock boost control). Otherwise you could do some basic datalogs with a 3 bar map and find the altered values to get what you want, but the volts to pressure method would be MUCH easier.
And for trans control, rememebr there are MANY different trans pressures that the ECM controls and references so the values displayed may not show what actual line pressure is. The ECM tables in many cases reference EPC pressure which in turn controls line pressure through the boost and main line pressure control valve. You need an actual pressure guage on the trans to ACCURATELY know what changes are being made to line pressure when you make ECM changes. So be CAREFUL making changes to the pressures as there are other multipliers that need to be applied to know what changes are being made.
And keep in mind just because you call for a value higher than the limits, you will not reach it as the DS4 has mechanical limits that have to be kept in mind. I will try and research some more to these mechanical limits, but for now this is what I have found.
