Awesome Andrew, UNA 12 is looking really good.
I see an issue with scrolling on pages, with a 3 column page, the column with the longest number of items will scroll to the end before the actual page will scroll.
Is there a way to set the desired column to scroll?
Yes, we are tuning up these sticky columns. Some layouts and combinations require extra consideration. The issue you observed is already being addressed. For now you can turn off sticky blocks in Page builder.