played with this theory today:

1. 'maf disable' (already commonly known, and labeled as 've enable')
2. what robert theorized is a 've enable' flag at bit 7@0x2029 allows both lookups to be used (how exactly what the calculation is or its weight is unknown)

all factory bins have both flags UNSET meaning that if it's true, maf disable being set will obviously use VE lookup anyway (otherwise we'd be running n-alpha or car wouldn't run)

the stock f-body MAF table on my car hits blm trims of 116-120 @ low RPM, and 130-134 at higher airflow (the whole table wants to be tiled a bit). my adjusted MAF table runs blm trims 124-128.

my VE table is narrowband tuned, has been painstakingly detailed until it was perfect. i've been running speed density for a month now and my trims are always 122-126.

first test: stock flags (unset unset) and crank VE. i set 10% VE flat. car started and idled ok. suprisingly the car ran ok, but during acceleration and decelleration it felt REALLY WEIRD. maybe it was the butt dyno, but throttle response was dead. this leads me to believe that some fueling events are influenced by VE regardless of these flags, but cruising range seems unaffected.

next test: run my modified VE table with a stock MAF calibration with both lookups enabled. as my calibrated VE table is 8-10% lower at low airflows, my trims should be higher than they'd be without the flag set.

results: running 've enable' without 'maf disable' (theoretically using both tables for lookup all the time) brought my trims at lower airflows to 128-132. that's a BIG difference, leading me to believe in this mode that VE is heavily weighted. the biggest thing was that it seemed really stable, like the trims were a bit on the high side, but there were no spikes or dips.

next test, set 30% VE across the board with 've enable' flag set. result, engine started and kinda idled, but bucked and died under throttle. i shut it off before it had a chance to hit closed loop.

tried calibrated VE table but a bullshit MAF table, 2% airflow. car barely ran for a few secs then died. this confirms that the maf is being used.

so this tells me that we can run a proper hybrid MAF/VE fueling mode, cool stuff

im going to develop a tune in this mode and see how the results are vs. pure speed density or a re-cuved MAF table.