I know that Square D HEPD80 calls for installation into a dual pole breaker but I currently don't have a space that's close to the main lugs since the wires that go to those breakers are very short (they have been cut to just accommodate those breakers).
I know that Square D calls for the installation to be as close to the main lugs as possible thus I was wondering if I could piggy back the two black wires from Square D into each of the single pole 15A breakers that are currently closest to the main lugs? The breakers are one on top of the other so they should cover both phases/sides of the panel since the panel is crisscross (Eaton Panel).
Why does Square D ask for a dual pole breaker?