Nice thread. Im going to throw a little hypothesis in.

Im thinking that transient is the new follower and coastdown the new cracker equiv.
So the idle tables with the 3 columns relate to static idle, coastdown/cracker and transient/follower

Ive been messing with these tables for weeks, though only one or two changes a day.
They can drive you a little insane, I do think the stock P settings cause some nightmares, a look into the hsv r8 tables shows some columns to be zero'd out as are different ones in the Z06 tune.

If you get pissed wipe out the P tables, then as Hymey says add them back once you get the rest done.

Perhaps we can come up with a 10 point plan for tuning idle like the old Desired airflow days.. It may also be the case that the E38 is actually a PID controller and we just dont have access to the D function. Or do you know its actually not there Mr H?