One of the Bibble Pro plugins that disappeared after the Corel takeover (to AfterShotPro) was the ability to work on an image in the LAB colour space. It was a very easy way to add “pzazz” to a flat looking image, and I wish we had it in PL3.
LAB operations tools in RAW developing apps are rare. Are you sure you cannot achieve the same result with curves in RGB mode?
I am not sure, but then I haven’t seen any tutorials on that …
It would be useful to select among multiple color spaces for the tone curves tool:
RGB, HSL, HSV, LAB,…
For demonstration purposes, here’s a tutorial for Photoshop that seems related to this feature request:
https://digital-photography-school.com/how-to-use-lab-color-in-photoshop-to-add-punch-to-your-images/ (@Mike_Murphy_1948, if this isn’t what you are talking about, please explain.)
Currently, PhotoLab works internally within the AdobeRGB color space. (See here and here for reference.) However, you might want to read here and additional discussion here. Maybe there are plans to add Lab as a working color space?