I have an old HP EliteBook 8530p, which does not support booting from GPT USB (GPT HDDs are fine though). Lately I had the wish to have a fast-to-start OS for browsing, smaller web tasks, etc., so I grabbed a ChromeOS build (latest one by ArnoldTheBat), flashed it on an 8GB flash drive, and popped it in. It did not boot, so I dug deeper and discovered that it actually is GPT, and cannot be converted to MBR.

As my laptop does not support UEFI booting from USB (there's a really-really beta UEFI support in the BIOS, but as I said, it only supports GPT hard drives, not USB devices), I'm stuck. Is there any way of booting it, say, another flash drive with a specific boot loader/manager (e.g. Plop)?