I thought kerma made a emissions safe tune for those cars...
I've been a diesel mechanic my entire adult life (20 years now). I worked on old school diesels and now work on computer controlled ones, which are more efficient and more powerful. I, like others, understand how to increase power in them. Why did VW cheat on emissions? To get more power, and better MPG. What happened after the "fix?" Less power and MPG, and now a national back-order of DPFs because they are failing at a ludicrous rate. Why do you think that is? Why does everyone that is able to delete them state they will wait until the warranty is up, and then delete them? The answer is because these systems are prone to failure, (not always, and there is more to it than a blanket statement, but I'm sure you get that already) hinder performance and MPG, and when they do fail are expensive to replace.
There are plenty of tuners out there that promise that they can give you a tune that maintains the factory emissions, and in fact they do just that. What they don't tell you is the increased wear on these items, and the inevitable failure that these tunes will cause. Just as with anything, the more you push it, the faster it will wear. Kory Willis was/is big on tuning vehicles and offering both emission intact and delete tunes. I ran PPEI on my last truck, and loved them. The problem is that with the truck increasing power of 120hp my soot load in my DPF would increase much faster. I could monitor it with EZLYNK through my phone.
I'm not trying to piss in anyone's cheerio's but rather just putting out the obvious. I'm sure their tunes are really good, even though they have some critics out there against them (as all tuners do). What I hope to do is that people understand what's going on when you run an emissions friendly tune. Remember that I'm only one data point in this whole equation. Doing a few quick google searches will net a ton of information on the ability of diesels with DPF intact tuning. I hope that whatever route you choose you have luck.
*EDIT*
To further clarify if you decide to do emission intact tuning your car will not fail the next day. It will wear out faster, and if you do a ton of shorter trips, then that will make it seem much more worse compared to if your commute is longer IE on the highway.