Zero Demand Ignition Tables (Haltech)

Apologies if this has already been covered, but I have been struggling to find information on the use cases and benefits of "Zero Demand Ignition Tables", particular when used with closed loop idle ignition corrections.

Now my understand of this feature is that on the Haltech platform, the Zero Demand Ignition Table overrides the base ignition table and all other corrections when active. It activates when throttle is below the User Demand Minimum throttle limit.

I have been exploring the Mazda RX-7 S7-S8 Haltech ESP base-maps where this feature has been setup with RPM on one axis and AC state on the other as per this image (http://imgur.com/Fh3sJUG). These ignition values are actually vastly different to what is set up in the base ignition table.

I would understand this concept if this had been setup as the idle control table, however there is also a Idle Control>Ign Corr map setup for this as per this image (http://imgur.com/sFFjyRV). To further confuse things, Decel Cut is also activated which I imagine would operate in most of the higher rpm areas of this table.

So my question is what is the rationale behind using a zero demand ignition table? What is the philosophy in tuning them in conjunction with Idle Ignition Correction Tables and Decel Cuts being run at the same time?

If this is purely being used to manage timing advance for AC activation, wouldn't a Generic Correction table be more appropriate?

Appreciate any insights people can provide on this feature!

From my understanding the zero demand table is a feature that comes from the zero aim tables in the older Haltech ECUs, and that dates back some time - I believe it pre-dates the introduction of idle ignition control. To a degree you could use the zero demand table to achieve something similar to idle ignition control.

When you have the option for a proper idle ignition control function, I don't personally see the usefulness of the zero demand table. In your particular configuration I can't see a good rationale behind the way the zero demand table has been utilised. I'd be inclined to rely solely on the idle ignition control correction table and disable the zero demand table.

Interested to hear if anyone else has input on this though.