It will be great to have some more filters in ER301. As ready-to-use blocks or kind of constructor blocks where you can create a filter which you like.
2,4,8 poles, different types (transistor ladder, diode, vactrol, … flavours) with some flavour and not sterile. Maybe just a filter with many parameters and users can create their own variants according to the taste. of course, I can filter all signals outside of ER301 but it will be very helpful to create big chains with internal modulation in the box. As a plus, it will help to take less modules for small live performances.