I’ve taken to leaving all tonal curves (filmic rgb, tone curve, base curve) off to begin with, and only applying it once the other adjustments are complete (white balance, color balance, tone equaliser, local contrast, contrast equaliser). Then all I have to do is adjust the ‘white relative exposure’ slider in such a way to prevent clipping in the histogram. ‘black relative exposure’ and ‘dynamic range scaling’ can also be adjusted to taste, but are of less importance. Even then, filmic rgb is not best every time. I snapshot my filmic rgb, and compare it to a base curve and tone curve, and keep whichever of the three looks best. It’s the best approach I’ve found so far.