Mamiya power drive back w/T exposures.

Just got this back, I do a lot of long exposures in T mode. just wondering if anyone has experience with it. Wondering if it will auto wind once I hit the shutter, or will it wait till I advance the shutter to end the exposure. Or if you have to automatically trigger the back to wind after the exposure.

Thanks

I assume you've tested this feature long ago by now seeing the date on this post, what was the outcome ? I'd seen the T/M.UP switch on the top of the 6x8 unit and figured that must have to be set when doing Timed or Mirror Up shots?
I wish those backs had been useful as a full 6x8 in Horizontal too, but apparently not......shoots as the standard 6x7 in that mode? Not a deal breaker at all, just would have been a real plus if it did.