1. Keyboard shortcuts! I really wanted to deselect items by hitting escape but it didn't work. I kept trying anyway because I'm so used to Balsamiq :) I'd also love to be able to hit / to quick-search the list of elements I can add, then return to add the selected item. Again, Balsamiq really nails this.
2. I wanted to add a div with Bootstrap's pull-right class, but couldn't figure out how. Some means to add custom elements with custom css classes, even in a limited way, would really help me.
3. I typed some text (directly into a grid .row) but it didn't show up in the CSS+HTML tab. Not sure if this was a bug or not.
I really want this to work and it would save our team loads of time (meaning, we would pay for it :). Looking forward to what you do next.