You'll get very little (but not zero) since the regulator maintains the voltage set by the feedback resistors regardless of load (up to maximum). That's one of the advantages of a regulated
mod, very little voltage sag under load. The main concern with a regulator is efficiency rather than voltage sag. Regardless of losses elsewhere in the circuit, the regulator will always maintain the set voltage. It's the losses in the wiring and components that become the primary concern.