From my experience, if you come to a stop during the regen it is over counting down to 0% and will work its way back up toward 100% before beginning another regen to 0% attempt. I have noticed regens starting as early as 80-85% at times, in fact very few times (if any) have seen it get all the way to 100% after the first time it did after adding it to the IPC.
I have about a 15 minute drive to work, and during that drive I will usually add +5% on the upward swing, and it is not long enough to complete a regen should one be started. I do keep an eye on my % Full Status and have done a pretty good job of ending up with 40 mile runs away from home when I am at 75-80% full and truck will generally kick into regen on the return trip and get to 0% before I get home. One time I had to drive a few miles past the exit to my house and got it down to 10%, so I went down an exit ramp to loop back and caught a red light at the bottom of the ramp and the countdown stopped and started back upwards from 10% to 15%.
Before I used FORScan to add DPF Filter % Status I know I was regen every other day for like a week coming home from work (because the regen didn't have time to complete). The regens were happening on the drive home, and then when I parked in the garage and got out of the truck I could hear the metal crackling as it cooled down, and there was a strong odor from the process in the garage that lingered. Since I added % Status to my IPC and kept an eye on it this has not happened.
FORScan instructions:
Add DPF Filter % to screen IPC 720-07-02 ... 0242 087C ... xAxx xxxx
This adds the DPF % screen to the Truck Information screen. Some trucks will report a camera error after making this modification. To avoid that, make your update according to the following: If your original default value is 0, change to 8; if 1, change to 9; if 2 then A; if 3 then B; if 4 then C; if 5 then D; if 6 then E, if 7 then F
Show Temps on Gauges IPC 720-07-01 ... 8409 8EA0 604A ... xxxx xE5x xxxx
Display exact temperatures above the gauge on the center cluster. Replace ** (EA) with E5 with brake controller, 65 if no brake controller. A5 adds temps above gauges without adding boost gauge and boost data to menus.
This is my first diesel, so a learning experience for me. I am thinking for long term health and reliability of the system it is probably a good idea to fully complete the regen events as much as possible; however, that may be just my thinking because by design Ford just expects us to drive it blindly and essentially end up with a lot of interrupted regens--even if you have a longer commute like 50 miles doesn't mean you wouldn't park in the garage in the middle of a regen as it starts when it needs to start, for my truck and driving it seems to be happening about every 325 miles +/-.
I know the ultimate would be to do what wreedsvt is planning which is to delete his truck after he rolls over 10,000 miles, then all this goes away and fuel economy likely jumps up 5 miles/gallon to boot.