Hello,
This is a good idea.
It’s not possible to distinguish between fiat/custom, only between crypto or fiat/custom. I can modify the frontend templates, so that each row has classes denoting whether the base or quote symbol is crypto or fiat/custom. Then you’ll be able to style the rows differently, or even hide one type or the other using CSS.
I can also do this for the main plugin’s UIs. Changes to the parent plugin must happen before any changes to the Exchange extension.
I will notify you here when I release these changes.
with regards