I'm doing two high intensity workouts a week.
FBW / each exercise is taken to failure with two further attempts after taking five deep breaths, so technically it's a bit more than just one set.
Three workouts a week would be doable short term but not sustainable, I tried that and I quickly stalled or couldn't recover properly, so two trainings a week were determined through natural elimination.
Hard to say if it's ideal but I make strength gains as an advanced lifter and save a lot of time.