If I’m right - a big if - I think making minor tweaks to filmic middle grey should be fine , specially as a final step. If all other modules are basically doing what you want them to do, then I see little harm in making a little grey adjustment in filmic if you’re almost done.
Setting the exposure right really helps to let tone equaliser’s masking to have a sane default , most of the times (at least, if you’re after making adjustments around middle grey and shadows , not extreme highlights. Then the masking needs an exposure adjustment). And color balance RGB does what you expect it to do with the sliders that affect shadows, mids and highlights.
After that is all set and you’re almost happy, tweaking a bit with filmic middle grey seems fine to me. I just never ran into that need. But I’m also quite liberal and 'quick n easy ’ in my edits.