I'm comfortable with all 5 basic box positions and 7 3-note-per-string patterns for diatonic scale. I can switch among these positions fairly well. Problem is, when I try to emphasize on a mode, it feels like I'm drawing on a blank sheet. E.g., let's say I'm trying to play dorian. If I think of it as an independent scale, i.e. not relating it to its parent ionian, but using the intervals to define it, then I need to memorize all of its position from scratch. As the starting/ending note of this mode is different than that of the ionian, my existing knowledge of scale shapes doesn't help me. This is true for any of the modes.
So, at this point I've started to think if I'm missing something. Because memorizing all 7 mode would require memorizing 7*(5+7) = 84 shapes. I'm not very sure if that is the optimal way to do it. Any help is appreciated.