Speedmaster spark plug holes improvement??

I wish they hadn’t edited out the exhaust stroke so we could see what was happening during overlap, but its interesting to see what’s going on there.
[EDIT] If you pay attention, all the work and effective flame front happens with the blue fire. Most of the orange fire you see (especially at the end of the burn) is only converted to “dead heat“, as it’s burning during the pressure loss caused by the piston outrunning the combustion gas.