Please consider reading the Ventoy documentation, if not done already. Both the Win10 and Linux systems offer some convenient GUI tool capable of installing a GrUB2-based bootloader once the drive got "initialized" (as a GPT unit on my CherryTrail); Combined to 'rEFInd' i found the likeliness to survive an "update" has improved while dual-boot became 2nd nature. Plus, read-only "frugal" mode booting from an .ISO image file might actually save the day when time is short, etc...