Typical , the jumpers are "just" out of reach im going to have to dismantle
the unit to access , likely need to wait to next week.
Is there any firmware i can put on an SD card that will start the unit from the card
without having to fully reflash at this stage ?
That's the reason why it can't flash through the SD card you just forgot to move the jumper.
About the firmware that you can boot through an SD card without flashing the control board, Bitmain doesn't have a firmware like that but BraiinsOS have a firmware that you can boot without flashing the control board.
However, you still need to move the jumper to boot through the SD card.