Born2BeMild,
Get a boost in rgb color is totally possible. What would justify switching to LAB could be only one result, just got in that mode.
I followed the tutorial, converting to LAB and applied an overlay of 91.1 in the last step.
The result seemed like something I could get without having to switch to LAB.
If you use the
same technique, and
apply the same values used in A and B, and contrast adjustments in L, for channels rgb and values, the result is very close.
Original left - Right using RGB
Below.
Using Lab - Original tutorial
Above are the results seen in
Ho-Hum to Wow! in Gimp