Hey, thanks for your feedback.
It may sound trivial to some, but EVERY fillup at the gas station is a stressful situation that more often than not ends up in overfilling and gas spillage.
Here's what I'll do, once I get the petcock and bungs installed:
Pull into the station 20 feet away from the pump.
Uncap the bung on the tank.
Remove oil dispenser from bottle cage (The petcock is closed and always on the bottle).
Screw oil dispenser onto tank's bung.
Push the bike up to the gas pump.
Remove gas cap, insert gas nozzle.
Open petcock valve while filling tank.
When finished, put the nozzle back.
Put gas cap back on.
Shut petcock, unscrew oil dispenser.
Cap the tank's bung.
Return oil dispenser to bottle cage.
This is gonna be one cheap aluminum oil dispenser by recycling my fuel bottle, which I bought for $5.00 on ebay. Petcock and bungs should cost less than $15.
I already put the oil into the fuel bottle. Until I get the valve/bungs installed, I'll just mix some gas in the bottle and pour it in while I'm gassing up.