just going to throw a curve ball in here. you could use a synth block with tracking set to off and have a square wave lfo with a low duty, or the sequencer tied to the synth volume. if the lfo is tempo synced, then you could control it's speed from the front panel tempo control, or by tapping the tempo in with your foot. you could also assign the synth block to any output you want. it would always be at the same volume (although you could continuously control this if you want) and you could start and stop it by bypassing the synth block with a switch, or via a scene change, or a switch attached to the "run" parameter of the lfo or the sequencer. did i cover everything?