Hi no need to worry about the DPF as that will carry on regenerating as normal, your parts removed are exactly the same as mine were and if you look at my post with the pictures of the cooler after I cut it in half you will see the crystallised Adblue has invaded the coolant area around the gas tubes, I also had a small amount of crystals in the expansion tank, this is not ideal and means the gas tubes running through the cooler have been compromised and are letting the Adblue steam and crystals into the water jacket but being as the coolant is heavier this tends to push the other way causing the syrup like substance in your pictures, the main problem with this cooler is the cooling length is to short and unlike most other designs used on older engine set ups which have a lot more narrow O.D. set ups but longer cooling runs our shorter larger coolers will always promote corrosion of the cooling tubes because of the heat involved being mounted so close to the DPF core allied to the fact Adblue rots all base metals, most other manufacturers mount the coolers on the outer fringes of the engine block where the ambient temperature in the engine bay helps cooling.
Steve.