I was thinking the same thing....such an easy conversion...cut the chimney, shorter glass, done!
Based on my experience with the lemo/Drop, I think cutting the chimney would actually improve flavor.
And I have it in my head (not sure why, or if it's even correct), that the longer your juice sits in your tank then the staler it becomes. Like it's pre-cooked by the time it reaches your coil. I'm a fan of frequent filling. Isn't this one of the reasons why dripping is so flavorful?
With the ease of filling the K5, I really don't see the need for more than 3ml. But that's just me.