Hi guys,
I just had this problem on the rear case of my MacBook Pro.
4 of the 10 were rounded.
I managed to get them out by filling the tip of the Pentalobe Screwdriver.
The cheap one I used has a tapered tip, so if you file it, it gets slightly bigger/wider.
Once I feel it has a bite again on the screw, I used quite a bit of downforce to make sure it did not slip.
I got them all in the end, the screwdriver needed more filling for the worst of them.
I hope this helps :)