Thoughts on Rear Subframe Braces

[Danimal]

I searched around, but didn’t find too much info. What are everyone’s thoughts on rear subframe braces, like the Technobrace or adjustable rennline?

Would stiffening the rear chassis help reduce understeer? My understanding is that softening the front and stiffening the rear helps reduce understeer. Or would only a sway bar help with that?

Thanks!