Not theoretically, but actually. For every spawn point duplicate in the spawn points array, you get an extra storage slot.
Unless i'm missing something, I would like some way to tell how many units are in a cannons stock. I usually fire off my cannons when I see they aren't building any more with some completely empty because I had my attention somewhere else.
Wish there was an easy way to know how many units are loaded in the cannon and ready to be fired. Instead of only knowing that 12 are ready when it stops building units.
Yeah - I mentioned this in conjunction with an earlier comment regarding visible build queues - the same interface could be used to show what is currently stored in the cannon, and is also generally useful elsewhere.