Customizing the Custom Game

I was looking at custom game creation (just for funsies, y'know.) and I was sitting there wondering why we don't have more control over the aspects of said 'custom game.' Obviously not messing too much (or at all even) with in-game mechanics (Scaling, Passive gold and stuff like that) but changing a few of the rules like how much gold each player starts with, what level they start at, etc. It would be fun to play a 1v1 and and not really worry about out cs-ing the other opponent; just worrying about the kit and such. Or just for the sake of theory-crafting new builds, testing match-ups/mechanics more in-depth and so on and so forth. Like I said, I was just wondering if there's a specific reason we don't have this feature/functionality. Or maybe, just maybe, no one's really thought about it? ;x