No intention to jack your post....but I think the problem lies with the mini itself and not the sensor and you might be spinning your wheels for no reason.
There seems to be a issue with a combination of the mini and the lack of development for the firmware development on this particular board type.
Just to be clear I'm not blaming anyone except 3dr themselves for pushing the mini into production and not having all the bugs sorted out prior or even having a fully operating FC for that matter......plus you put into consideration all the effort is being put on the pix 2.......that may or may not ever make it into full production before the technology becomes obsolete lol.....so who knows how long it will be before there is a consolidated effort to having the mini up and running.
Your best bet is to try and get your hands on a full sized pixhawk and save yourself weeks of frustration....unless you know your way around git hub and the code in which case I would gladly be a tester for you!!
Wish you all the best.