I had an SD Countryman before my F55 and I could never really tell when the DPF was regenerating. As far as I understand they are all active and passive. What I mean by that is that they will be passive (work when the exhaust Temps reach a certain limit) and active( the car forces the engine Temps to rise by different ways, i.e increase fuel, to force the DPF to regen) when the car detects a certain difference between the exhaust pressure before the DPF and that after.
The only time I knew for certain my Countryman had been doing something was if you stopped the car the fan ran on for a while to cool the engine as it runs at a higher temp during active regens.
I did read an article somewhere saying that on the F55 and F56, the DPF was placed closer to the engine and also more insulated, meaning that it's gets to temp quicker and stays there longer so that the regens work better.
Hope that helps, I did look into DPF's a lot before getting my Countryman. I think that on the whole the BMW engines seem to have less issues than other makes.