The Blender3D addon allows you to select all islands/shells and their corresponding faces of the desired individual UDIM/UV-space/UV-tile. To do this, select the island/shell of the desired UDIM/UV in the "UV Editor" mode and press Alt+L or select the corresponding item in the "UV Editor > Select > Select UDIM-Matching Faces & Islands Alt+L" menu. This is the zero version, it was made for me. Thank you for your feedback.
Version Zero. Any feedback and suggestions.
This extension does not require special permissions.