Why are not flexible variants allowed to be used with signed urls?
Our business need is quite simple. Upload images that are not public, and then serve them in different sizes using dynamic url resizing along with a signed url for security.
In the current solution, we would have to create several variants before uploading the images. This is troublesome, as our future clients would perhaps require another variant size. In addition, we would need to maintain a variant register, in order for our clients to determine which variants to retrieve, instead of using standard width/height when retrieving the image.