Porsche tables / tuning strategy 991 GT3

I decided to make a bit of a project out of self-tuning my 991 GT3 for E85 + Exhaust using HPTuners MPVI2. I have oodles of experience with other EFI systems, but never a P-car and very few DI cars. There are a few things fundamentally different about this ECU vs what I've worked with in the past.

I have been searching for answers from those with prior experience, mainly regarding the fueling strategy, and I was wondering if anyone here has experience or knows of resources specific to 991 generation Porsche ECU that could answer a few of my questions. I hesitate to contact some of the established tuners out there because I feel like they would (and should) regard their expertise as proprietary.

Some of my questions:

DI Fuel parameter changes for E85:

The most obvious thing for me is the "injector slope" variable, (ms per% of fuelmass) which should globally increase or decrease the fuel proportion, however I'm not sure if other values need to be changed, such as injection clip / max injection window and a few others. Also, looking at the tune I am under the impression that this car runs a split injection strategy (up to 60% relative load & 3K RPM) ... should I lower the load/RPM of the split injection due to higher fuel volume for a given rpm/load?

Airflow section:

I will be experimenting with a few different exhausts (possibly headers), have drop-in filters, and would like to optimize the airflow tables / V.E. prediction instead of just relying on closed loop to accommodate changes in V.E. from mods. I think I have a fairly good grasp on how the engine is calculating VE from the pressure fill and valve overlap tables, but actually implementing effective changes in a way that's familiar with more simplistic "VE table" tuning seems a bit daunting. Is there a "best practice" for tweaking the airflow calcs in a predictable way?

Torque model:

I have heard about throttle closures and torque reduction issues for these cars, looking for insight on how to remedy this. Being that ~10% torque gains are likely possible with mods and tune, my first thought is to raise the reference torque-to-load table, but I'd imagine that could possibly shift which loads request a given amount of airflow / ignition timing. Another thought is changing the reference / normalization torque by 5-10%, or just experimenting with the torque calculation tables until getting results...

Ignition timing:

I'm fairly surprised that a car with two DI modes, variable intake manifold geometry, and VVT on both cams just uses ONE base timing table. Seems dead simple. I cannot find an ignition offset table using VVT condition as an axis. The "Split-Injection" timing offsets are zero'd out in the stock map. The "Low Octane" spark table shows only 1.5 degrees of retard under lowest octane condition above 6k rpm, leading me to believe the engine relies heavily on knock feedback rather than finely applying learned octane variable (lol@ the "electronic octane" sticker on decklid)

Another thing that confuses me is just how "jerky" the base/primary timing map is in some areas, with large swings in timing cell-to-cell (esp from 4.7-5.3k rpm) and some RPM columns that have timing *increase* as load also increases at that RPM. How much of this behavior is to optimize emissions rather than tuned at MBTT? Being that E85 has *faster* flame front propagation vs gasoline at some AFR's, I'm concerned that these base values might produce excessive cylinder pressure, compounded by how E85 is so knock-tolerant. My first thought is to smooth the table out, pull a degree or two globally, and go from there. I would reserve some time on a load-cell dyno to tune more or less cell-by-cell for MBT in some of the more important partial throttle areas.

Attached is stock timing table from 991.1 GT3

Any help would be appreciated, thanks!