Yeah I would think you can log the dead legs only if you aren't 135 current/checkride, etc...
To add to this logging time question with a little bit of a different senario...I did a search on this topic and did find a few confusing thoughts on it...Part 91 gig-Corporate company with a King Air 300 in the right seat? Would it be logging SIC and multi turbine time if the PIC has the "SIC required" on his type rating?