I think most of these are still valid -
https://yabb.jriver.com/interact/index.php/topic,99096.msg685880.html#msg685880the linked thread has the descriptions and reasons why they are useful
The requests that are specifically PEQ filter requests are;
- selectable HP/LP filter types & slopes
- all pass filter
- advanced biquad (i.e. enter biquads directly)
- change the shelf option to actually be Q rather than being S (and allow larger values)
and the PEQ usability change is;
- export/import PEQ filter banks from/to a defined text format
The other things in that thread would still be useful mind you such as ability to rename channels & break apart mix target from output format.
Thanks for asking!