Is there way to change player traits within Forge?

I would love to change the player traits so that I can test them on the map in spartan mode without having to leave forge and go into custom games. Is there a way to do this?

Not in halo 5, unfortunately.

I hate when the forge monitor explodes.(spawning fire effects)
Scares the -yoink!- out of me!

Set to invunerable would be great.