For Tremulus Lune aux LFO
Pretty simple. One aux LFO in parallel with, and speed-modding to, the main LFO. Main LFO speeds up with volume. (Or slows down, if inverted.)
Speed-modding LED requires a Height control– a 1K or 2K parallel pot.
So three total new controls: aux speed (10K or 100K, depending), aux depth (1K or 100K, depending), and aux Height (sets top speed; 1K or 2K, whichever works best.)