Infamous reversing dash frame screw

Not taken as a smartass. In the past trying to do something as simple as changing a dash bulb can be difficult (for me anyway). There are some basically impossible, as well as anything "under dash" related. Our 67 cuda is ac equipped, radio, console. All that stuff is difficult to work around to say the least. While removal of bucket seats, console isnt difficult. It does add to whatever task your tackling.
With dash "tipped down" during this task, the access I have had behind the dash is way better from above and thru windshield then from underneath. Removing the AC heaterbox/heatercore is different then the standard heaterbox.
I'm not trying to be a smart *** but, why would you want to remove the dash as in why make it where you can remove it with windshield in? Other than taking my car down to bare metal for restoration I cant see where you'd have to remove the dash. The heater box drops out easier than a pickup truck(easiest heater core I've ever done) with the dash in. The radio , steering column pedals all that stuff comes out with dash in.