"As far as optimal TT positioning, most of the previous photos posted in this thread show the captain positions are not pushed forward anywhere near the legal limit."
"That is just an example, of course there are "legal limits" to how far forward you can push the saddle and so the "superman" positions are outlawed."
"Yes there is a UCI 50mm behind the BB minimum"
"even if their rules allowed it."

It makes me curious- to what extent ARE there tandem time-trials that even fall under the UCI rules? I assume none of the long-distance stuff (RAAM, various 24-hour, 12-hour races, UMCA records) is, and I'm not aware of any short-distance tandem events locally, period.