Was searching to improve GTmetrix and overall load speed of our site.
Came over this:
Question is as follows, as i understood from this forum post and replies, there is a work order on serving images sizes dynamically from DB, but theres no ETA, this is 3 years ago, any update?
As we load extreme contents from the CMS, serving scaled images for all our pages would force us having 30+ fields just for images in the CMS, So… Is there an update regarding the dynamic sizing?
Best Regards!
Currently all regular images are optimized responsively, not sure about dynamic images. https://webflow.com/feature/responsive-images
But you should be running all your images through tinypng or similar compressor before uploading anyway. I try to get BG images under 300k and inline under 200k. This is best practices no matter what Webflow does with the images. Not sure if that helps.
3 months without a clearification on wheter this is working or comming? @Brando any update or knowledge about this? 
All images including ones uploaded through the CMS go through our responsive images tool as @DFink mentioned.
As of Dec 21st 2018 we started working on a CMS image gallery that will allow multiple images to be uploaded to a single field in a collection.
You can learn more here: CMS Gallery | Webflow Wishlist