Nautilus thumbnailing (many potentially large) files is blocking GUI, usuability improvement suggetsions
I am watching this now for years and it seams to stay unaddressed.
Thumbnailing is not only slow (OK when many large files) -- but is getting more a usability issue as it more or less blocks the nautilus GUI when busy updating many icons. Also drag and drop seam to stall a lot when this happens. In some situations deadly locking nautilus and I have to kill it.
This applies to many simple jpeg images and also to other default file formats. And similar applies to custom thumbnailers. I am talking about 1000+ files here in one folder.
I suggest to better manage the thumbnail processes and give them a low (nice) priority if exceeding a larger number to files to be processed to not bog down the machine usability.
Also the gtk level "thumb nail" update of the actual generated icons seam to have a impact. This rendering process also must be managed better to not impact GUI operations.
Another related issue: When updating thumbnail icons in the file view pane -- those often shuffle around crazy (icon size changes oddly temporary, etc.) for no good reason and selecting/working with files is a bit painful. Also when inserting new appearing files -- it should be tried to not shift currently selected/highlighted files and maintain the location/scroll pos and only move icons before/after the active selection if possible.