1.401(a)(9)-5 q/a#2 speaks of what happens if a participant receives more than the minimal amount, but only that it can't be used to reduce future minimum distributions.
to me that would imply you could take more than just the minimum.
The only thing the regs seem to say is once you reach 70 1/2 (or terminate) to satisfy the rules you have to take out at least $x, but I see nothing there that says you can't take out more.
I think the issue would become: there is no 20% withholding on the minimal amount, but if you take more - then what?
for instance, what if the person took the entire balance?