Here's an actually good suggestion

[Butanal]

No need, if this needs to be done I suggested a tool a while ago that allows to easily do that ingame :

Addon suggestion: MapPatcher

Hi ! Here’s a suggestion for an addon I really appreciated on my TTT server that Muffin told me to suggest : MapPatcher. It used to be sold on GMS then the owner decided to open-source it, and it’s available here. Here’s the deal : this addon provides a simple tool to delimit areas and volumes of any shape. With this tool, you are provided with multiple brush types : player clips, prop clips, normal clips, bullet clips, forcefields, hurt / kill clips, remover, you get the point. So, here are …