if coming to a stop after downshifting I generally just let it slow to a stop, as it will go back to "D" when it is fully stopped.
I'm not sure what you're saying.
If you leave the shift lever over in the normal leftward position, and then use paddle shifters, it will always return to D after 10 or so seconds of not touching a paddle--no matter what. (You can also pull and hold the left paddle to force it to return to D.)
But if you slam the lever over to the right, to Tiptronic manual mode, it will never go to D. You can use the lever OR the paddles to select a gear.
More importantly, in Tiptronic the system will auto-shift the DSG up and down to protect itself from over- or under-revving the engine.
I think that was the question: do you put it into Tiptronic, shift it yourself when driving (paddles OR shift lever), but let it shift itself step by step down to 1 automatically (instead of you shifting it down) as you slow down to a stop?