I'd like to add that all this stuff is highly image dependent. My criteria is, "does it look natural?" That comment was made in the video about the grass and that's where the tone filter is great. It's easy for some things to take on a harsh or wax museum look if you go too far. If the images are very good to begin with, DFS (with no tone filter) numbers beyond about 2/100 give problems. I have images where 2/50 is about the limit before I start to see problems when pixel peeping. OTOH, on other images I go way beyond that, so there's really no general rule. Experiment!
Right on the button. Each image is unique and subjectively evaluated. I find, for example, that on scenery type images a 6/45 is excellent.
When you first try Tone targeted, you have a tendency to over do it.
Play, experiment, trial and retry. Perhaps the least used tool is the A/B button which allows you to see if you made it better or worse.
Fred