Ventoy
Copy ISO files to USB and boot; no reformatting needed.
Ventoy is a free, open-source tool to create multi-boot USB drives. Just drop ISO/WIM/IMG/VHD(x)/EFI files onto the drive, and Ventoy handles the rest. Supports BIOS, UEFI, Secure Boot, and a wide range of operating systems. Unlike Rufus or Unetbootin, you never need to reformat the drive to add new images.