No offense to anyone with a Scan Gauge (I think they are pretty awesome but don't want one on my dash distracting me.) but honestly, I don't understand how people aren't noticing regens even without a Scan Gauge. In my car, its pretty obvious. My car very periodically regens (about every 300-400 miles, as is to be expected) and when it does so, the idle RPM goes up to around 900 as opposed to the normal 780 or so, in conjunction with the fans going from silent to hurricane force in no time. Instant MPG suffers, and I can hear the engine become ever so slightly more "diesel" sounding with the extra injection event.
I haven't (and don't plan to) ever shut it off in a regen, though I have already experienced quite a few with 2200k miles on the clock. I simply continue to drive it while it is still obviously regenerating, and then as soon as the idle drops again and the fans spin down to the usual speed, I continue to drive for a few more minutes with ample coasting in gear to help cool down that turbo and exhaust system ASAP. Done.
Is my procedure necessary? No. Does it make me feel like I'm saving my turbo, avoiding DPF clogging, and minimizing oil dilution with fuel? Absolutely.