There are a few things that would be nice to have. I put them in a single issue but I can split out if you want.
[ ] button to edit settings or code of current field/action/subform etc.
[ ] filter doesn't work
[ ] cluttered all the icons on the left. only show on hover?
[ ] should be some indication that elements can be dragged into layout. perhaps change cursor. or see the drag icon on hover in this github checklist
[ ] DnD should insert where dropped
[ ] indication of field type. perhaps via icon. or hover
[ ] how to get to import/export etc?
[ ] switch edit pane on open
[ ] clicking arrow doesn't collapse side menu (click name does)
[ ] click element on left should do something. edit primary info? (layout for form and settings for field etc)
[ ] use id in sidebar but also display title
[ ] plone toolbar. even if its not used much in IDE mode, it should still be there. It can be collapsed to reduce space. Need a way to logout, and go back to normal plone mode. It's perhaps confusing to have this as a different mode over the normal DX forms
[ ] resize size of editor vs explorer
[ ] can't select text and turn into hidewhen or label.
[ ] cut/copy/paste
[ ] keyboard shortcuts like Ctrl-S.
[ ] use icons in editor tabs to save space, e.g. replace "settings"/"code".
[ ] delete inside settings is unintuitive.
[ ] view/preview button mode. ideally a split page frame with live preview that updates every time editor pane is saved.
User problems
There are a few things that would be nice to have. I put them in a single issue but I can split out if you want.