Would the Leap Day Working Have Worked?

Short answer: no.

Longer answer, parts of which could not be included into the story "Leap Day" without disrupting the story's flow:

1. Various things on both Earth and elsewhere in the Multiverse needed to happen in order for the Edomite to achieve his apotheosis. Between UNTIL's actions in the Gulf of Mexico and Antarctica and Barnstormer's sacrifice above Kansas City, three of the things which the Edomite saw in his vision at Nan Madol in 1968 which were necessary for the dimensions to align correctly did not occur.

2. DEMON required the mass slaughter of civilians world-wide to provide the raw power for opening and stabilizing the breach to the Qliphotic Realms. VIPER did a good enough job disrupting these attacks around the world that not enough energy was being fed to the summoning circle on the Pyramid of the Sun -- a fact which neither the Inner Circle or the Edomite was aware of yet at the moment the story begins to focus on the Working.

3. Shadow Destroyer masquerading as Chantal in the Inner Circle was about ready to kill the Edomite himself and hijack the Working for his own apotheosis. It is debatable whether there was still enough energy being generated world-wide for him to have succeeded, either.

And then, of course, all bets were off the moment Captain Chronos dropped Starforce, Ladyhawk, and the original Doctor Destroyer back into the normal flow of time in the middle of the Working...