I make some indepth log analysis. Finding the biggest positive jump of about 16*. On high rpm converted to ms is not much and can be compensated. On very low rpm around 1000 it can be a little enough to be felt a bit, since it converts to something about 1.5ms reduction of dwell. I still needs to find the exact condition when this can happen and to fatten the dwell in that range.

Now on the decel conditions, the issue seems to be fueling. The dfco have some spark blending recovery, so you don`t get a 40* jump but slightly increasing the advance in couple of jumps of 3-5*.

Also plan to increase the high rpm dwell to compensate for the 2 inbuilt Gm timers. What do you suggest as the max on-off time in percent that will not decrement spark output. I am sure some visiual testing can be done on your rig, with different on-off settings for 5-10 minutes constant running.

Not sure if you can make some DYI pressure chamber. A thick plastic box with a thread for a spark plug and a hose for pumping some 10-16bar pressure.