The Network Limit Upload File size in the Network Setting is tied with the pro site setting for the zero level site. Which is required for limiting file upload space.
HOWEVER the Network Admin Upload space seems to be tied to that lowest level, Level zero.
And even when assigning the main blog to a higher level pro site, the Network Admin interface is still associated with the lowest level.
This is a SIGNIFICANT limitation, as this means the network super admin can not upload files to the network beyond the Level Zero space allocation.
Either the Network Admin should be unassociated with the space allocation limitation, or it should adopt the Main Blog Pro Site Level.
Please look into this.