It will be interesting to add support for multi volume to choose which volume (SD or USB) to mount.

Usefull for new boards like SKR 2, GTR, Octopus etc

It added to Marlin menu with this PR : MarlinFirmware/Marlin#22004

Multi volume are working in Marlin mode but not on TFT mode.
In Marlin mode print menu gives access to the ability to browse onboard SD storage and onboard USB storage on the motherboard.
In TFT mode we have only access to the onboard USB storage with OnboardSD icon but not to SD storage when MULTI_VOLUME is enabled in Marlin.