This update is going to be powerhouse. Seriously, great work @charlie! A few comments / thoughts below.
1. Modal Esc Key Close: Great new additions to the modal, canvas, and dropdown elements! Noticed that the Esc Key Close setting doesn’t appear to do anything on my end when using Modals.
2. Dynamic Content 2.0 Noticed that when using the Twig syntax in the html editors throughout the site, the double curly brackets are marked as errors but all looks good when using the Global > Twig eidtor.
3. DC2.0 Thought: This is more of a thought than a fix – I may just be dull but I was definitely confused at first why all of my newly selected dynamic content was showing up as in 2.0 syntax vs 1.0. I know I enabled it in the globals but was originally under the impression that just the “Twig” specific DC would change (math, templates, etc). Came here to originally log it as an issue and then re-read the docs.
Ended up having to go to an old site to figure out the 1.0 syntax I needed for this solution. That said, I totally get the move to 2.0. Just going to take some getting used to 
4. Twig Error Warning: So if you’re manually typing Dynamic Content 2.0 you’ll get the “Could not render…” message as you’re typing. Which is totally fine but the bright red feels like CS is mad at me 
What about a softer message box like the mockup below? Perhaps, if possible, waiting XX milliseconds before displaying the error could be nice as well since sometimes you’re just in the middle of typing. Obviously, just my 2 cents.
5. Font Menu: This is pretty slick! Love the previews and the ability to include/exclude the expanded preview. Noticed that the initial “Font: Inherit” font looks a bit out of place though in the UI.
A few general comments / kudos:
V Flex and H Flex: These are awesome!
Inline Dropdowns: This is a game changer for mega menus as the tab order is properly preserved!
Sticky Bar Fix:: This is great! Appears to be working well.