The current saving process in the Designer interferes with the preview feature and some other functions. You cannot activate preview while changes are being saved, and this makes the working process very tedious and slow, because you have to be constantly waiting for auto-save to finish to be able to preview changes.
Not sure if I'm the only one getting this, but it's the single most annoying issue when using Webflow. Saving is always getting in the way of your work. Even when opening a page, it starts saving before doing any change, and it makes everything slow. I hope this gets fixed with the React implementation.