Shouldn't be a problem at all. Computers are fast. Also, the code I showed you exits the For-Each loop as soon as it finds the match, so it saves some time.
The greatest slow down will be Blitz itself performing it's collision checking on all of the entities that you set up for collisions.
The greatest slow down will be Blitz itself performing it's collision checking on all of the entities that you set up for collisions.