KRunner's functionality is amazing, but too much of its power is hidden in the UI that gets brought up with alt-F2 or alt-Space. Kicker and Kickoff expose an interface to KRunner as well, but with only a small whitelist of plugins that don't reveal its' true power!

I propose removing the whitelist and enabling all plugins that are enabled in System Settings > Search > Plasma Search, for consistency: it's odd to have things enabled there but not show up in the user-visible interface in the menu.

If that's too controversial, I propose whitelisting a few more plugins:
- Unit Converter
- Calculator

The Windows Start menu has these integrated, and users who use them there may think that we don't have this feature, when we actually do, but it's just not available in the menu.