I think it’d be a great feature to have local adjustment presets, working much like the presets do for global adjustments. A user-friendly implementation would be in the context menu of the local adjustment masks themselves. The current menu shows these options:
Add “Apply preset adjustments” and “Save as preset adjustments” to this menu, so I can apply my hair preset and then tweak the sliders as needed, for example. I’d at the very least be customizing presets for certain often-repeated tasks like skin smoothing/shine, eye sharpening, reduction of dark circles, brightening the shadows of faces, darkening skies…
The current workaround some people use for this missing feature is very cumbersome. With that little bit of tooling described above, this would be useful for everyone doing local adjustments.
[Edit to clarify: I agree with @mwsilvers, the presets would be for the sliders and HSL tool, not the masks themselves. The workaround people use involves saving as a preset which includes the mask; inconvenient as that needs manual rework each time as the mask isn’t the relevant part here]