Ah you can actually dismiss the onboarding panel from the command palette, sorry that wasn't more obvious! The sidebars can be collapsed with ⌘+; and ⌘+', thou

Ah you can actually dismiss the onboarding panel from the command palette, sorry that wasn't more obvious! The sidebars can be collapsed with ⌘+; and ⌘+', though we also intend to make them fully resizable soon too! You're right about the undo/redo stack, we need to improve its integration with the system so those work properly. Thanks so much for this feedback! Keep it coming!