Spring RTS Engine

I wonder if there is any standard agreement on the river rule, namely that you can not/should not/is impolite to cross the river with your commander very early in the game. It's been a sort of a gentleman's rule but it isn't really followed.

Ofc course applies to maps with a clear river/partition in two halves.

Can it be enforced with lua code?

It probably can, a line could be drawn halfway between the start boxes and commanders trying to cross could be pushed back.

But why would you want that? To prevent combombs? Maybe the best way to deal with this is just to allow commanders to dgun each other and live by reducing the commander blast radius significantly.