have an option to remove full size photos from mobile after they have been synced to classic
Once a photo has been uploaded full size to lightroom mobile and then downloaded to classic you should have the option to remove the original from mobile and replace it with a smart preview.
This is the response I got from tech support : "buy more storage space"
When I said that I didn't need more they said to do this:
1. upload images from Lightroom mobile
2. then open lightroom web and download all those uploaded file to local storage
3. after that delete those files from cloud to free up space.
4. And then import those downloaded images in Lightroom classic.
And sync them with cloud.
Once you sync those images from classic then they will be uploaded as the previes in cloud which will consume very minimal space
