I fully agree with @robb, the main missing feature of WebTop is documentation both on how to use, how to install and internals.
Probably WebTop developer would like to hit me with an hammer, I told this thing so many times!
Another most requested feature is support for CalDAV/CardDav, many users requested it in person during various meetings and you can find the same request also inside discourse.
I don’t see think a specific layout for tables is needed, we should focus more on more responsive UI for smartphones (or phablet).
Could you elaborate a bit please?
In the end, I don’t think we need to add many new features to the product, we should focus on improve existing ones, open up the software using APIs and give the basics for creating an ecosystem where anyone can join the effort to build a better groupware platform.