My finding was that Hubitat uses HSV even though it appears to be labeled HSL in the attributes (which creates confusion with the SwitchLevel dimmer related attribute for level). And that hue is expressed in the range of 0..100 instead of 0..360, presumably for legacy ST consistency.
With those things taken into consideration, I used the conversion formulas from the wikipedia entry for HSV and HSL and then later confirmed that the Hubitat conversion libraries give the same results when performing conversions.
More chatter here from a previous discussion: Shelly RGBW2 doesn't respond to Hue commands
