L67 "In Gear" Trigger

Howdy,

Does anyone know what the PCM is using to determine if the idle needs to be changed due to the transmission being in gear? I have a stand alone for the 4L80E and I've copied the transmission settings and code status from a 97 F-body with the L36 and T-5 over but have issues with the idle surging in Park/Neutral as it no longer knows/indicates it's in gear. I gave up trying to get the 4T65E code to work on the 4L80E as the gear ratio mismatch put it in limp mode every time and those tables aren't enabled for the L67 to do it directly.

Options:
1. Share the Pressure Manifold Switches (they just go to ground) with the Microsquirt
2. Wire the PRNDL range switch as the Microsquirt doesn't use them
3. Do both 1-2
4. Bypass the whole proper "in gear" by retuning the AC tables to function as an "in gear" and wire the AC request input up to the P/N switch so that feeds the correct condition. I think the side effect would be the fan would kick on regardless then.

Thanks