What side of the chain do those tensioners work on? If the "downwind"(following) side it will pull the cam timing "retarded" and will retard cam timing worse than if the chain slip was allowed to "float". Though it will hold it more consistent and not "bounce"as the chain does wear.
I have a problem with all of the new fangled engines, many with multiple chains even.
I never thought a steel chain scraping/constantly rubbing a plastic guide was ever a good idea.
For the same reasons as brought up about nylon coated cam gears becoming brittle and chipping and breaking with heat/cold cycles it's like your building something you want to fail.
I begrudgingly have 2 4.7 equipped vehicles in the driveway, gritting my teeth dreading the day the timing system fails on both of them,
There should have been laws forbidding the big 3 from phasing out their tried and true small blocks. I so wish I could have gotten both of these vehicles with 318/360 magnums instead.