Ok so I've just replaced the crank position sensor thanks to some valuable tips here. My .02 cents are: definitely go with the e8 female torx bit, 1/4" drive. 1/4" to 1/4" extension. I tried the various other suggestions ( 1/4" hex, 7mm hex, 1/4" double hex) and none were successful.

Also, I'm curious: what is my next course of action if the same stalling out symptoms and check engine code repeat?