Not sure if possible, but right-click on widget with option to close all isolated environments and ability to select each one to close individually.
Or maybe in tray icon.
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Right-click switching between ReHIPSUser profiles.
i approve this one
Closing isolated desktop from desktop thumbnails view will be a great idea. Don't know why it hasn't crossed my mind. Don't know yet, will a small X button be added to the top right corner (will be hard to click if there are many desktops) or right mouse button click will close it (may be clicked by mistake). Added to our TODO list.