[ This is Background Research, just in case such might later be needed? ]

Just FWIW a decade later there are now (plausible?) alternatives to usbmount (e.g. pi-usb-automount below, not just devmon included with udevil) that we could hypothetically consider in future? e.g. if worst case usbmount proves insufficient for community needs &/or inadequately maintained:

• pi-usb-automount is "USB flash drive automounting for a headless/console-only Raspberry Pi."
  https://github.com/fasteddy516/pi-usb-automount

• Description: "This is a modified version of udev-media-automount created specifically for use with Raspberry Pis and USB flash drives when a full desktop environment is not installed. (i.e. Raspberry Pi OS Lite, headless installations, kiosk and other purpose-built applications, etc.)

  Once pi-usb-automount is installed, a USB drive will be automatically mounted and accessible in /media/usb0 when it is connected, and will be automatically unmounted when it is removed. If multiple USB drives are connected, they will appear as usb1, usb2, etc."

Originally posted by @holta in #4100 (comment)

A few related issues & associated progress:

• Rename usb_lib_umask0000_for_kolibri to be more generally applicable #3907
• [Upload2USB] Writing N times to /tmp as part of file upload (before copying to USB stick) damages SD card #3924
• PR usbmount again #3944
• [Upload2USB] USB Stick Double Mounting - user gets permission denied error when uploading file on Ubuntu Desktop 24.04 and 25.10, Mint 22.2, and Debian 13 Desktop #4066
• PR update temp_dir php_value for upload2usb #4086
• PR WIP detect double mounting [for Upload2USB] #4088
• PR [Upload2USB] Add check for double mounted drive; Simplify getTargetUSBDriveLocation #4097