A PMV *is* a check valve, you don't need 2 before
If this was not in a box, didn't have to be put away after use I would agree. With my certain setup I will pull it out of the shop, out of the box, connect the filter tower and start pumping. I have to do the reverse when putting it away, so the tower will get disconnected. My hope is to leave as much under pressure as possible (all but the hose really).
It will look more like PMV > quick disconnect > hose > check valve > filter tower > PMV.