I have a Hitchhiker device which can be used for an SRT ascent. The friction hitch on it has slipped a bit on me a few times. It was disconcerting but I think not dangerous. It did catch eventually. A second seems like a very long time when you are sliding down.
Had to look on YouTube for the hitchhiker device, I wasn't familiar. Looks like there is still a mechanical device required and a pulley. Looks interesting but I don't think an SRT ascent could be more efficient than it is with a MR Safeguard and a hand ascender.
It seems like the recreational tree climbing community awards the effort for the most complicated way to ascend a tree...and we're trying to find the most simple method with the fewest moving parts!