Permanently disable time machine prompting for external disks

Is it possible to disable time machine prompting when inserting external disks?

I use an appliance with SATA disks that regularly formats the disks. Whenever I plug such a disk in I get prompted again for time-machine - since the time-machine opt-out file is deleted.

This can happen 10s of times per hour and is rather frustrating.

I'd be happy for total disable of prompting, but better would probably to make it per interface (ie USB - i use a USB->SATA device) or per device (ie just the SATA dock I'm using)