On EK at least, it doesn't matter when or how you check in, as long as you get to the airport in time for departure! Some airports have specific conformance times when you need to scan in at security (DXB at T-60min, LHR being very strict comes to mind) but that airport specific not EK.
FWIW I never print out a bp. Ever*. What's the point!
Except when not printing it costs you money: hello FR!