Fingers crossed. I always update mine via the developers SWDL menu so I've never seen that screen. The SWDL you see what is going on although it must have continues power to the unit else you are back at square one. The normal method as you say pickup from where it got to except it unwinds back a bit. Yours may have unwound a fair bit. Normally it completes in about 50 mins. It could be that with the unwinding bit after stopping the car it will get there...Today Im try update maps to 195 but looks like something is wrong... It update from 0% to 100% in around 15-25 minutes but then stuck at 100% for more than 20 minutes and then I need to leave car... I use same card as allways(SanDisk 128GB Extreme PRO 95MB/s) Will see what will happen when I will came back after work(I know that normal update continue from where it has been stopped)...
I recall that mib tool which you now have unlocks the developers menu normally this is done via Odbeleven / VCDS etc. You keep pressing the hold button till two screens open up. First is the normal one with the FeC details keep holding then a second one opens with the SWDL menu on it if that's been enabled. You can use that one but you must open the door every 15 minutes else if it loose power in the next 5 minutes, you have to repeat the whole process. Advantage is you get to see the progress and you get use to reading what it's doing.
Mib2 high units fully validate the contents of the card via the SLA1 signature so will not import into the car a corrupt card so it is unlikely to be that. You do still have those interesting FeC issues as you reported on the software thread. Might be back over on that thread you need to go where the experts are on the unit. It is troubling that they somehow got into the unit via your dealer / workshop then replicate into additional once mib tool did it's work. One for @jpmedia over on the software thread or any of the others, on the other hand it could be your unit needs a little longer to run on the update and may well run happily. I've never come across invalid FeCs, they on the other thread will have done. It's something very odd that has happened.