Moving a large folder makes UI stuck and not loading

Any time I move a large folder with many files through the UI, and the disk IOPS gets higher, the UI dies and impossible to load it. Why doesn't "move" files operation use a separate process or thread?

It seems to block the main thread and notebook can't be used until files movement is completed, took about 7-8 minutes now, until folder copy completed, and it was impossible to load the UI, but copy can be both restricted on resources, lower "niceness" for CPU load, and be in the background to not interfere with the UI webserver thread.

Any ideas how to fix this? Or it's by design?

Here is for example the IOPS rate and the UI was dead all the time:

Start by reproducing the issue through the UI while moving a large folder and trace the move operation that blocks the notebook UI. Done should mean the UI remains usable during large folder moves, with the operation isolated or resource-limited as appropriate.

Written by the indexing model from the issue text.