I'd be interested to hear some guys here ...how high have you pushed volume? This could be anything... no days off, long workouts tons of sets, full body Ed..just the most you have tested out the "more is better" approach.
I've personally never pushed too high...I know one arms workout I did Serge nubrets workout. 8 supersets of bi and tri, then repeat for another. So 32 total...to failure...until towards the end I didn't care lost focus
Think it was press down/cable curl x8
Dips/barbell curl x8