If the jailbreak script can run on arm linux, you probably can get close enough by using a raspberry pi and a power bank. Configure the pi to automatically run

If the jailbreak script can run on arm linux, you probably can get close enough by using a raspberry pi and a power bank. Configure the pi to automatically run the jailbreak as script on boot or when the phone connected via USB and you'll get a portable plug and play jailbreaking device.