For enduro/Downhill I absolutely think bar to saddle is a great baseline. You can adjust up and down depending on trail steepness, personal preference, etc. I got clued into this by an article on the "other site"
https://www.pinkbike.com/news/importance-of-handlebar-height-mountain-b… awhile back and it totally changed my riding comfort once I came to terms with the concept that maybe the bike designer didn't actually design the large and XL frames with appropriate stack. Here's an excerpt: "For example, the new YT Capra 29 has a five-size range going from small to XXL. YT recommends the small to riders around 160cm, and the...