With a pitch like that, I would prefer to see it in action against a batter - and not necessarily in a game situation either. I'd like to see the pitch worked in the zone, how and in what manner it reaches the batter, and the complexion it has with or without movement.
To me, a pitch like that has to have a certain "take" to it. Velocity or the lag thereof, is good, but how it (pitch) acts as it comes in is a look-see, is to me, worth the trouble of setting up. I'd also like to see how you posture yourself throughout your delivery. I know the pitching surface may be an issue, so try and manicure your mound the best you can. I would hesitate to suggest pitching off a flat. A knuckleball has a dramatic style to it, like night and day, when pitched off a flat rather than a mound.
I'd also like to see that pitch from two different view points - one from the back view of the pitcher, slightly off center, then the second view from behind the catcher slightly off center.