Photoshop/Lightroom: Skin tone tool

yes, the new Hue tool would have been a perfect fit for skin tuning, but they went a different direction for some reason.

automatic Sensei-based skin areas selection

You can achieve this using the Color Range Mask with the local Graduated Filter or Adjustment Brush along with the Color Range Mask control. Then use the Hue control with 'Use Fine Adjustment' checked. You can take up to five samples with the eyedropper and then adjust the Color Amount control to isolate it to just the skin areas. It works quite well and very close to the desired "automatic Sensei-based skin areas selection."

In the below example I dragged a Graduated Filter off canvas so the whole image is selected. I used four eyedropper samples, which selected all of the skin areas and nothing else in the picture. You can use the Exposure and Saturation controls to adjust luminance and saturation and Tint and Temp controls along with the Hue control for fine tuning the skin tone