How big is a pitchers projectability?

They are saying you have not filled out yet. Quite often pitchers after they fill out their MPH goes up. Pedro Martinez gained 35 LBS and 10 mph on his fastball after he signed

With your size, you project more speed, but you probably need to improve your mechanics that will traduce in more speed and more control, and if you add experience, (hard work) could be the road to success.

How big is a pitcher's projectability?

Consider this: Is a BIG pitcher projectable. You can search any college or pro team roster and find the greater percentage of throwers are 6'-2" or TALLER.

You have the height for projectability. The weight will show up, possibly by family genes or by college life in general. A coach has ways to help you put on the weight also. A coach will also instruct you in the mechanics that offer additional velocity.

But remember this, control of your pitches is as important as velocity. Work hard at both.

This may also support my point:
Nolan Gallagher, JR 6'-2" 200lbs
Stanford starting pitcher vs University of Texas, 2/16/07
High School: A 2004 graduate of Red Lodge High School • Did not play high school baseball because there is no prep baseball in the state of Montana but did letter four seasons in basketball and once in cross-country.

He supports the height issue.