My Mix Balancer tool may be of use. You can use the All Faders [+] and [-] buttons (bottom left of GUI) to bring up and down all non-group faders at once:
The [-] button also changes colour from yellow to red as the loudest fader reaches it`s maximum in the mixer. The headroom readout also shows how the dB value of the loudest fader. Pressing the [G] (“go to”) button takes you to the track with the loudest fader aswell.
https://forum.renoise.com/t/new-tool-3-0-mix-balancer/44382
