In Asia, We are allowed to race with the 4300s. Almost everyone here are deadshorting the GP cells. I have done so myself. I am no expert compared to some of the gurus on here
but I definitely felt alot of punch after dead shorting the cells
and you do sacrifice a little run time, the discharge characteristic of the cells is very nice, once you felt the car slows down, the next lap your car will be completely dumped.
Just make sure you completely discharge your cells on a proper discharge tray before deadshorting for safetly issues.
I only deadshort my GP cells, for IB cells I always keep at least 450mah inside them for storage and discharge them on the CTX-D2 before charging again!
This is just my findings.. If I have pointed in the wrong direction, please advice.