Make reinforced windows harder to break

[Sundance]

I've broken out of the brig with my shoes, I'm pretty sure. the trick is to throw them, not hold them in hand

This.
Throwing damage needs to be looked at, not window damage threshold.
Throwing a pen should not do any more damage that attacking someone with a pen.

In this scenario; hitting a window with a chair should be faster at breaking a window than throwing shoes at it. In the current situation chucking something at it will break it surprisingly (obnoxiously) quickly.