Please think about this:
The digital filter is no doubt nice, but 1. Lacks of all features of filter3 and 2. SADLY new filters cannot be neutral in “dry” Position: even with 100% cutoff/rez 0% etc. Those filters affect the sound with minimal cutoff.
Imo you should consider to 1. Un-deprecate filter3. 2. Change the new filters so they can have a neutral state and take the bitter pill to write a translation function for redux 1.0->1.1
You could also Un-deprecate math device. I mean, will you improve It? I guess not. Is it use a lot of times? Yes. Is it an essential renoise feature? Yes. So why hiding it?
At least for renoise. Would it hurt, if filter3 is not deprecated in renoise, but deprecated in redux? (So the dau vst user won’t be confused by all those filters)