Didn't see the renewed activity until now. It might be worth putting together the driving conditions and regeneration observations of those that experienced DPF failures.
For example:
driving pattern: my car spends most of its miles on one hour long fast highway commutes.
regen intervals: Since the fix I observe regens at irregular intervals, sometimes as soon as 50 miles after the previous finished regen.
regen OBD display change: For some of these regens the soot load display stays live, i.e. not frozen at the maximal value like before the fix, and one can see it decrease as the regen proceeds.
DPF max load change: Before the fix regens always happened when the DPF load reached 23.45 g (have to double-check this number). Now the max soot load (but read from a different OBD location) seems to be 24.01g, but I have observed regens happen at 12.x gram or 17.x gram.
regen temperature change: Sometimes the DPF temperature goes significantly higher than the 600-630C that seemed normal before the fix, well into the 700's.
regen duration change/irregularity: Sometimes the regen seems to get stuck, lasting well over 20 miles.
So it could be that either defective DPFs are installed, or that they are damaged during install, or installed improperly (e.g. so they are under mechanical stress), but from my observations it could also be that the regen parameters got modified and now create higher thermal stress on the DPF. Or, as mentioned, that there is another undiagnosed fault in the exhaust system that causes the DPF failures. Initially my replacement DPFs did not let soot escape, at least not to the point that observable quantities would be deposited in the tail pipe.
In any case, this creates an unsustainable situation after the extended warranty runs out. Unfortunately the failures are not happening fast enough for the 'lemon law' fix failure clause to kick in.