Hi. I am installing a EGT soon to monitor just that. This chip does deliver more fuel and I understand that can lead to increased temperatures. I use the chip conservatively for that reason. Looking at the normal temp. gauge I haven't noticed any difference. Once I get the EGT in I wil be taking notice of the temps with it on and off to get an idea. I have the chip wound right back until I am able to see what is going on with the temps. Even wound back it makes a difference to the car though so I suggest cranking it up would provide more power but to what detriment I am not sure. I have also noticed an increase in idle of about 50 rpm when the chip is on. I don't notice any difference in the boost readings be it on or off (still max out about 12 either way).
This is my first diesel and from what I hear overheating them is a bad thing. That's why I am just taking it easy and installing the EGT.
There are plenty of other chips out there as you would know and they vary greatly in cost. Some claim to do more than the DONATOR or at least differently. Maybe they do, maybe they don't.
Can't help with the extractors - no idea.
When I get the EGT on (weeks not days) I will start monitoring and post again. Cheers.