NASA hasn’t had a man-rated space system in use flying since 2011, so maybe it’s a bit premature for anyone to be looking at using black holes for propulsion?
Maybe once we can get a spacecraft out of LEO (again, after 40+ years) this is something to be looked at WA-A-AY down the road...
Interesting theory, but...Cart before horse...
“A man’s reach should exceed his grasp,
else what’s a heaven for?”