Yes, seems to work on any permanent shop as long as you deploy PDS with 0 time left on final circle. Not easy! You have to survive quite a bit until then, and then the gas tick system of increasing damage is still in place so you can buy 20+ masks but they will start to break quickly once the gas gets stronger.
@@Ps4stickgod do it when the last circle fully closed, the circle indicator on the left side of screen should say #7 with 0.0 sec left then drop PDS. the hard part is getting to this point in the game because at this point you nearly almost won already
