I started editing my photos on Lightroom (holiday) and came up with this problem too.
I don't want to sync the photos to my desktop, I want to export as many photos I want to the camera roll at Max ress. It's annoying rendering 15 at a time when I have 100+ edits.
It's been 5 months since this post and the problem persists. Please let us export!
Same issue on my iPad running iOS 11.3. When I hit the share button -> save to files - I can max choose 15 photos (I want to export 500 files to my Synology NAS)
I wonder who’s fault it is (maybe it is an IOS/apple thing rather than a problem with lightroom). Can anyone from Adobe answer this?
You can vote for the feature request and comment here.......
If you read Josh Haftel's (from Adobe) comment in that same thread it may provide you with some answers.