I added a timing suite to measure each part of the triangle fill. Run test and then when you stop test you will see the percentage computation time of each part of the process. This will run about 16% of the normal stamped tri fill, since the timing blocks use up alot of computation time.
The results are: Stamping: 34% Computations: 20% Custom block overhead: 17% Set Size + switch costume + effect: 11% Point direction + goto: 7%