Images in BB/Themer not working with CDN

I just realized that background row images in Beaver Themer/Builder don’t get picked up by the CDN I use (ShortPixel AI). I saw a post here about a similar issue at BB Caching absolute file references however I don’t think I can easily redirect to ShortPixel’s CDN using the filter suggested in the post. ShortPixel uses adaptive image resizing and their API URL is https://cdn.shortpixel.ai/spai. Here’s the page that’s a good example (the background image in the header.)

Is there a way to make it work?