hi friend,
yes, when you unlock your mix window and open mix type, then you see "mix x offset" and "mix y offset".
for triple screen without edge blending use this like:
-layer 1 on mix 1, mix 2, mix 3
-position mix 1 on left screen, mix 2 on middle screen, mix 3 on right screen
-mix 1 "mix x offset -2", mix 2 "mix x offset 0", mix 3 "mix x offset +2"
and then load a movie on layer 1
...hope to see you in frankfurt;-)