Wow, 20 boards! We have Ctrl + B and then you can hit a numbered hotkey to switch to boards 1-9. But it sounds like a text autocomplete like in Slack would be necessary with so many boards. We'll look into that.
Hey Jerud, we just released an update with part of this, so you can collapse agenda sections.
Hey John, good idea. We did this partly, with previews for attachments that are images. Showing previews for other content types is still on our todo list.