That is unless it's already possible to do, and I just missed it!
What I'm wanting is the option to have the guardian boundaries always visible on the floor, that way I always have a visual frame of reference as to where I am in my physical room, allowing me to around my playspace with more confidence.
This would be especially handy in games like Dead and Buried, Rec Room paintball, and anything else where lateral movement is encouraged, because I'll know before I move if I have enough physical clearance to do so without having to wait for the guardian walls to possibly kick in. I know the nose gap is still a thing, but it's not always a good option in the heat of battle, and it takes you out of the experience.
A toggle like this exists with SteamVR's chaperone already, but I don't want to have SteamVR always running if I can help it.