I have a folder with large amount of images. It would take a long time to generate thumbs for the whole folder even with lowered thumb quality and size.

Is there an option for the thumbnail browser to only generate thumbs that are listed on-screen? So you could scroll to the middle of the folder and not need to wait for it to rendering what was skipped over? Thumbs don't cache so it is wasteful redoing this if when I move back and forth directories.

I also noticed that if you select an unrendered thumb while it is still generating thumbnails, it behaves as if the "Auto-scroll thumbnails during creation" option is checked until it reaches the selection, despite having it turned off. It's easy to notice if you open a directory and hit 'end' so the selection jumps down.
Using "view">"Refresh selected thumbs" after stopping thumb creation doesn't do anything on unrendered thumbs. I imagined it would attempt rendering them.
Excuse me if I missed something and thanks.