I've had this issue with the wedge brackets.
The wrench or socket seems to always come off and i crack my hand on something.
Then there is the fact that the bracket and carpet cover the bolt hole making it more difficult.
Let's not forget that the subframe seat brackets get nuts on them, which makes it even more of a pain.
Maybe we are looking at this the wrong way, wonder if it's possible we should be putting the bolts in from under the car, giving them a tack weld so they don't move and installing nuts on the top similar to the studs in the front.