I think what @Gyromike was saying is that he is using Bridge code in Blynk to communicate with multiple devices that have different auth codes. The server setting would be the same, but there would be multiple auth codes, one for each device.
This is the recommended way (in fact the only real way) of passing data between devices and is quite common.
This post from @Gunner explains the basics in a sort of “Blynk Bridge for Dummies” way
