Looking for something inexpensive and portable that will run GNU/Linux.
More difficult than it used to be now that machines can be locked to Windows.

Is there any way of testing whether a laptop has an unlocked bootloader before buying it?
(assuming the seller will trust me enough let me run such a test!)

A salesman is likely to say it's unlocked merely because the salesman does not understand the question.

Willrefracta boot on a machine with a locked bootloader? (likely not)

Will refracta boot on a laptop without a hard drive at all?

Might laptops insist on getting an EFI partition from the hard drive in order to even read a USB stick?

-- hendrik