I agree, DEF is DEF, I to fill my DEF tank at a truck stop that sells bulk DEF. When filling the truck I have a Blue Peak container I saved and refill that too when on trips so when I'm low I don't necessarily "have" to go to a truck stop.
I'm not real wild about stopping at truck stops only because some drivers are slobs and spill diesel right where you need to stand to fuel, then yours shoes smell like diesel for the next few days, NOT good.
Dan