Only a guess, as I'm not largely a guitarist and don't have access to a Big Muff (that sounded wrong on several levels) to confirm, but Big Muff was also
my guess, given the 'onion' like iridescent livery under warm incandescent light (seeing how Access named the effects on food flavours and colours, depending on the original colours of the pedals).
The original Big Muff 'tone' control is also a combination of a low + high pass filter (not just a standard tone control), which would fit with Access' implementation of the control. And the input/drive control on the TI could equally act as the Muff's Sustain.
Unfortunately Access stated they would never confirm which pedals were emulated due to legal reasons.
__________________
PS > And another thing! Will the Ti|3 have user customisable/importable wavetables?
A ribbon-controller or XY-Pad might be nice, too, please! Thanks!