I can’t really find any information on where one would submit a feature request for KDE products – it seems wrong, to me, to submit them to the bugtracker.
I found this Reddit thread that seems to say that there isn’t one, but that post is, as of writing this, 6 years old, so I’m wondering if anything has changed since then?
You could do that. There is a wishlist option under the “Severity” drop-down selector. But , as you can imagine, what one person wants ranks pretty low when it comes to severity, so more severe bugs will tend to take precedence.
But, know this: KDE is not a a company with a suggestion box. it is an open-ended, grassroots, volunteer-based community with undefined, permeable edges. This means you can become part of it. If you want something, you should become part of it and contribute to making it happen.
If you don’t know how to code, or think you have nothing to contribute, do not underestimate yourself: you definitely have something that can help KDE. And, even if you end up contributing to something that has little to do with what you want done, you will be helping, however indirectly, to making your wish happen.
So hop in!