Lets start with the basics: what is the goal?
For timing, there are two ways (really one) way to 'time' the DS4 IP.
The one timing aspect that most people focus on is the physical mounting of the pump (aka TDCO) and 'advance' it as much as possible without throwing an error code. Am in the camp that this has little benefit to a computer controlled IP (and hence the comment about really only one way to time a DS4). Physically advancing the IP's timing is definitely effects how the DB2 (manual pump) works, but has a very limited effect to the computer controlled DS4.
Toward the original post about tuning via computer, this is the best way to manage the DS4's timing as it is dynamic based on data tables. Tuning on your own via computer is definitely possible where only a few actually go this route (to my knowlege, there are maybe 10 people in the whole world (that I am aware of) whom admit to this) due to the steep up-front cost of the software. Most people end up working with one of the paid 6.5 tuners (possibly only one left) to make a change to the programming as it is far less expensive to pay the ~$400 - $500 rather than buy the tuning software and hardware.
So back to the question of the goal. There are people willing to help toward making the motor run as efficiently as possible given its configuration (type of turbo (OE, ATT, Holset), fuel modifications (FTB), etc), but the thread will quickly go quiet if the intent is to make soot.
