The reason why the SB produces more vapor than you standard batteries is PFM
The SB at full charge operates at 4.2v . Here is the difference with a discharge rate of 1.5c it allows a maximum of 2.4A. The 510 atty having aproxx 2.5ohms of resistance plus the 120mohm internal resistance of the battery, less than 300mohm through the SB itself = curent requirement of aprox 1.615A. As you can see the SB allows the atty to run at its full capacity. At 6.784Watts the atty is happy

. IMO the SB enhances the flavor if anything, as far as vapor production I hope all this jargon summed that up for you.

To add to it USB is limited to 500mA or .5A whichever you prefer thus running the atty at only 2.1Watts.
Watts = power = heat
Notice how hairdryers are rated in Watts?