Idle Transfer Slot on secondaries?

You can run without PCV. But these carbs are designed to pull about 3 cfm of the ~20cfm of idle air from the PCV. Without PCV, the air has to come from somewhere else...such as small holes in the t/plates.

I no nothing about Progression Ign Dist......but if it does not allow you give the ign timing at idle that the engine wants, then that is not Progression....that is going backwards.
Sometimes the simple ways are the best ways......like a std dist with adj vac adv; also very reliable.