I tend towards the least powerful interpretation of abilities and stuff; I'd be willing to side that the prototype can't use the X1 title, because inquisitor, with the x1 title, would be throwing 3 dice and adding a critical all the time with only a premium of 1 point paid.
That seems too much to me, especially when the V1 title says what's on the maneuver dial, and vice versa the advanced's x1 title.
Edited by joewrightgm