Are you having problems with rendering skin tones from within Lightroom, or are you having problems with color rendering in Lightroom in general? I have been experimenting with Adobe's DNG Profile Editor (see this thread: https://photography-on-the.net/forum/showthread.php?t=602420 ) to try to get better color rendering out of Lightroom. This approach is not skin-tone specific, but, in my initial experiments, has yielded much better scene-specific color rendering.
I have not used any skin tone correction plug-ins so I am not sure how they might give you better skin tones in a particular context. It sounds like your skin tone issues are somewhat subjective (maybe?) and that the plug-ins, etc. give a more pleasing tone (warmer, or whatever) versus a more accurate representation (maybe not?).
In any event, in my limited experiments with the DNG Profile Editor, I have been impressed with the improvement in color rendering from within Lrightroom when developing and employing a custom recipe scene-referenced color profile. This approach may give you a better starting point for developing or deploying presets, etc. from within Lightroom to get the look you are after.
hope this helps,
Kirk