Back to matters DPF.
I've had a look at a couple of the O'reilly videos as mentioned by C5. Jimmy seems to concentrate on the air pressure differential and getting that below 10, ideally below 5 at idle. With that in mind I done a forced regen (using the while driving option) and I've taken a few more screenshots:
The first is c.3 kilos after the forced regen completed. The measured and calculated soot figures are considerably lower than they were 3 kilos after the last automatic regen which I guess is encouraging. However the air pressure figure is up at 12.6 at idle.

The next shot is taken c.15 kilos after the forced regen. The interesting / concerning thing here is the difference between the calculated and measured soot levels with the measured one increasing at a far higher rate than the calculated one... and that was predominately in traffic free conditions. The pressure figure has come down to 8.2 which, I guess, isn't too bad.

The third is from VAG DPF... I just wanted to ascertain how it calculates the soot % as I don't see that anywhere in OBD Eleven. It seems that it's based on the calculated figure rather than the measured figure which suggests automatic regens are also based on the calculated figure.

Anywaysanall... having digested the above I'm far less concerned about the ash level as that seems to be entirely calculated. It's deviation from the 320,000 expiry rate is probably relevant, suggesting my car is doing too many automatic regens. However, I'd have no qualms about resetting that figure to zero as the fire risk is associated with the soot figure. Conveniently there does appear to be an option to reset the ash figure independent of the soot figure so I'll probably do that soon enough... certainly before it gets to the 80.00g full level.
I think the next logical step in trying to reduce the number of regens and narrow the gap between calculated and measured soot levels will be pretty much as prescribed by the good doctor i.e. a bottle of diptane combined with another forced regen but I'll let the soot levels build up a bit first, probably!
After that I'd be inclined to think about pumping the aerosol version of the stuff panel uses into the air sensor tube. I don't think my pressure bleeding bottle would provide enough pressure to use the liquid stuff Jimmy uses in his videos. I do have access to a compressor i.e. there's one in my sisters garage so I guess I could look into getting a bottle to work with that. Unfortunately the cheaper aerosol from AutoDoc isn't an option... they don't ship them to rip off Ireland!
I'll post updates if and when I do any more, regardless... if only for my own record... I haven't got round to setting up a spreadsheet for it yet!