Do You really solved this problem.
I'm trying to use this driver in non bulb mode (essential with A7S Star Eater) and I never achieve this operation.
1) No data is saved on A7S memory card (that non a big issue)
2) The photo saved on PI card is always wrong

Just have a look on my first post here
To add some new information, when connecting to the A7S, I supposed that a first photo is engaged and when you try to take a photo, in fact Kstars/Ekos deals with the previous one. In this situation you cannot use astrometry and focusing, since all the intelligence is applied to a wrong image!