SUMMARY
The Device Notifier "Ejects" USB thumb drives rendering them unusable until they are pulled from the port and re-inserted. This is both unnecessary and poor work-flow. There is no justification for ejecting a USB thumb drive.

A much better action would be for "Unmount" to be the default action instead of "Eject". This would allow multiple actions to be taken on a thumb drive without continuously removing and re-inserting it, such as reformatting or burning and ISO to it. This is especially important if the USB port is difficult to physically access, such as the back-side of a monitor or PC.

STEPS TO REPRODUCE
1. Insert thumb drive and observe Device Notifier pop-up indication that a drive has been inserted.
2. Select "Open with File Manager" from access options in Device Notifier.
3. Select the up-arrow button "Click to Safely Remove this device." using Device Notifier.

OBSERVED RESULT
The USB device is no longer listed in attached devices via "lsusb" although it is still physically present and cannot be accessed until it is removed and re-inserted.

EXPECTED RESULT
File system should be unmounted but the physical device should still addressable. 

"Safely Remove" when referring to a USB drive should only unmount the device, not eject it from the bus. Ejecting is only preferred if the physical device requires that for access such as with a CDROM/DVD. Unmounting a USB drive prior to its physical removal is sufficient for file system safety.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: KDEneon LTS 5.12
(available in About System)
KDE Plasma Version: 5.12.8
KDE Frameworks Version: 5.56.0
Qt Version: 5.12.0

ADDITIONAL INFORMATION