Does the X825/X855 support USB boot

Does the X825/X829/X855/X856/X857/X862/X872/X835/X832 support USB boot?

Yes.

• Refer to Updating the Bootloader

OR

• How to Boot Raspberry Pi 4 From a USB SSD or Flash Drive
• Refer to https://geekworm.com/community/forum/topic/18912/pi-4-boot-from-ssd-using-x825-and-x735#post-317469 or download File:Pi-boot-from-SSD-public-v1.0.pdf