Three first areas for reflection:

  • A filter, you’re right, rather stereo and not too wide because of your current case (e.g. Dual Dagger, Zagrzeb, Polaris).

  • An attenuator or attenuverter, Basimilus and others will really need it... (e.g. Sinc Defero, 3x Mia).

  • A random, for 'generative capabilities' (e.g. Turing Machine, Wogglebug).

Other people here, more expert than I, will modify or complete these initial suggestions.

'On ne devrait jamais quitter Montauban' (Fernand Naudin).
https://soundcloud.com/petrus-major/tracks