I would be more worried about a cracked piston than rings leaking. The engine could last a long time with burning a little oil because of rings, but a cracked piston could come apart suddenly. Of course I am still waiting to hear what you have for compression and whether you can isolate this to one bank (or cylinder) by pulling plug wires.
Regardless, I urge you to get the EFI all sorted-out with this engine; drive it for quite a while before an engine rebuild/upgrade. No use sacrificing another engine on the Holley altar...
And no, don't let Holley, or their forum, tell you that you need a "perfect" engine to continue getting the tune sorted.