Dave: have you tried 34 degrees on the timing yet?
All the stroker bb we have taken to dyno have liked between 32 and 34 .
On the track, in the high humidity/ heat here this time of year, i will go to 35 or 36 as long as we dont lose anything.
We run pretty lean in this air- 13- 13.4 , any richer than that we lose time and mph.

If we are at 700 ft for track with a 3400ft da and sitting on 12.8 - 12.9 afr at 34 degrees of timing and off our number , i will pop it with 36 degrees to help with water grains and that pops our afr back up, usually gets us back towards are number.
Cooler weather/dryer air- our engines always like 34 degrees timing .

Just thinking with you.
Can you download your afr data and look at it for the whole run?
fwiw- I have one carb with Doms tune in it and , like you, tried a bleed change and it didnt help.
Once i got to where i could see the afr charted for the whole run- bleeds were dead not from Dom- fwiw.