Thought I would post this in case it helps anybody else. I have been seeing the distance between DPF regens falling on our 2016 Mazda 2. They have been happening every 60-80 miles recently.
I bought a bottle of redex DPF cleaner and added it with a usual bottle of redex diesel treatment that I add every 3 months. Using forscan I checked the last 2 regen intervals and they were 105 and 115 miles respectively with no change in usage.
I am not sure if this will be a temporary or permanent improvement but for £6.50 from Toolstation for the 250ml bottle of DPF cleaner it was worth a try.
I also noticed a rattle from the rear of the car and found both fixing points for the heat shield above the back box had corroded. This was an easy fix with two 40mm penny washers held in place with the original 10mm nuts.