Nothing that will go against Trinity's philosophy (I don't want to lose this lightweight DE either and I don't want another plasma), but stuff like:
- An option to use kwin-x11 as a window manager as well as configuring kwin effects (wobbly windows, etc.) so using an outdated compiz or beryl/emerald is not needed to have cool stuff. - Desktop notifications for applications that integrate with Plasma's notification system. - Kdeconnect capability to integrate with mobile phones. - A visual tablet configuration window, even if it's just a wrapper for xsetwacom.
May add more later on if I think of something that wouldn't go against Trinity's philosophy, but would be useful to have.