This is patently false. I followed the recommendations to the letter and mine is in the shop again. The first time at about 290 hours needed a new reformer because it wouldn't complete a parked regen. This time at about 610 hours it failed to complete a parked regen again. This time it is getting another new reformer and a muffler, (DPF). It has been in the shop since early October. The mechanic said that this time almost $8,000 in parts. I think this system may work better if I used ground engaging implements but I don't. I use mine for backhoe and loader work and no matter what RPM you run your tractor at there just isn't enough load to get high enough exhaust temperatures.
Your issue is only one of the failure modes of the reformer based DPF system used on the B3350.
In my case, is was/is exhaust over temperature causing immediate engine shut down.
Since I purchased my (fully up to date) B3350 new in 2018, it has completed precisely 1 operating regeneration without failure/shut down. No problems with parked regenerations.
Yes, I too was told by Kubota (not dealer) representative that it was operator error before I demonstrated that it was not.
It sounds like Kubota is doing to your tractor what was done to mine when it was in the shop for 12 solid weeks, i.e., replace reformer, DPF, check injectors, pump and timing, as well as (in my case, at least) other procedures.
Since return, I've been reluctant to use it because I must pay to have it hauled to/from my dealer each time it fails and may also need to convince Kubota, yet again, that the failure was not due to operator error. Dealer bills me if Kubota declines warranty coverage as has already happened once.
I am anything but confident that the regen issues with my B3350 are resolved or even that it is possible to do so.
Shame on Kubota.
SDT