I don't know much about diesel emissions systems. Catalytic converters require and add heat!! When they put them on the Harleys, it started cooking us riders. Recirc'ing unburnt fuel is not much of a performance penalty and may evening bump fuel efficiency.
Most of the problems are in the DPF just like diesel trucks. They have a collector that is porous that catches fumes that the Catalytic converter didn’t stop.
Once the flow is reduced according the sensors, the system goes into regen controlled by electronics which diverts fuel into the device to burn off what’s been collected. Since the fuel is now being used to burn past the engine exhaust, it doesn’t produce more usable power.
The electronics “decides” if it needs to happen or not. That’s usually where the issues start. They are programmed for what they think are the normal uses. If your use doesn’t match that they account for, it can lead to issues eventually.
If I was going to buy a newer high HP tractor, I wouldn’t be able to avoid it. But, I didn’t really need a high HP large tractor, so I bought a L2501 and skipped those “potential” issues.