I’ve seen the STFU used by pros on their DH and Enduro bikes, you also have Eddie Masters VHS tape both are currently in my garage, was planning to try them on my old noisy bike, ended up with a new bike for diff reasons which came with a ribbed chainstay protector.
Will try each next year, looking at each of them when they arrived, I could see them both working well, I think the STFU might have the edge as it contains the chain, the VHS tape you trim and apply where you need it, which would be both CS and SS IMO.
EDIT: Both arrived fine via international shipping with no issues