I used them on several motors through the years. Always with a good double roller timing chain. There is NOTHING wrong with trying to better control the timing, so it makes sense why you'd want it.

That being said, on my last build, when I took it apart to freshen it, mine looked EXACTLY like AndyF's picture above. I can't tell you why I had some success before, and later not. My guess is it has to do with how tight the chain is to start with. When the chain is really tight, you really have to preload the spring on the tensioner. I'm guessing that side load really digs in sometimes, and not others for whatever reason.

For the record, I won't use them anymore. Not worth the risk in my opinion for minor gains.