FWIW,
While testing numerous versions of SDM for the TX-1, I discovered that, if a microswitch is wired on the Normally Closed side instead of the Normally Open side, many, but not all, USB related features would operate as expected.
There were no deleterious effects to the camera/USB port from booting with power applied and then breaking power to trigger. Some events were actually faster this way and triggered on the press rather than the release of the remote button.