I made this a while ago but forgot to mention it (oops). This system is pretty nice, and works quite similarly to CloneTrooper1019’s Show Decompsition Geometry plugin, in that it’s a handy alias to the setting that is otherwise hidden within studio.
It’s very straightforward in how it works, it just enables or disables viewing your place’s navmesh. You can get it here:
https://www.roblox.com/library/2343139678/Toggle-Navigation-Mesh