bypass a low voltage shut off
This has nothing to do with low voltage.  It sounds like a feature to turn itself off after you haven't used it for a while to avoid killing the batteries.

This logic is probably encoded in a microcontroller deep inside the product, so is not something you will be able to change realistically.  Without getting into the details of the device that we can't know about, you have to trick the existing logic somehow.

Perhaps you can install a button on the front that interrupts power when pressed.  This glitches the power to wake up the device, so it will be on while.  This could be automated, but that could get annoying if it power cycles and resets just as you are shooting.