Config nodes in subflow modules
Currently, we cannot use nodes that depend on configuration nodes inside subflow modules because there's no way to configure the server property of those nodes. There's a post on the forums with a similar issue.
Visual cue for nodes/groups/tabs that have content in their description
I mentioned that in Slack some time ago. When I add content to the description of a node/group/tab, I put an emoji (
) at the end of its name as a flag. It would be great to have that added automatically, maybe using FontAwesome's file-text-o icon.
There's a similar feature request here.
Themes related (obviously! 
)
Theme plugins listed in the palette
This would make it easier for users to know when new versions of themes are released.
Theme selector in the UI
It's already there but commented out. I don't remember what's missing for it to be released.
SVG Icons
The only way I found to change their colors was using filter: rules. And creating those rules is a pain.
This article describes how to use them in a way that we can set their color with a CSS variable.
Grip
Since it's a PNG file, there's no easy way to change its color using CSS. I had to overwrite it with an inline PNG. This could be using an SVG instead.
jQuery
I don't know if part of the jQuery styles is missing from jquery.scss, but I had to create customized styles for parts of it.
Oops, most of the themes related topics here look more like issues. I can report them on GitHub if needed.
