There are many different codes. All the ones i've seen were in GUI. I would gladly tell you but i trashed them long ago when i thought i was done with this game :/
There are sme ope-source, some that are extremely laggy like the polar-escape ones, and others that are good and locked or even open-source.
The basics of it is, unit enters region, every X second of game time move unit forward.
A good way to say space would be to make two regions instead of many small ones or one huge one. When they enter, activate skate-code. When they enter the second rect, turn-off skate-code. Then you can use that saved space for the boundaries, unit enters rect - kill unit, which also takes up a lot of space depending on how wacky the pathway is. However, you could convert points to a rect, so you could technically get a really wacky boundary in with just one code.