because vege time is on a biological clock, and assuming we don't cause it to go off with stress or whatever, i'd expect any pruning reduces yield, but only what you cut off, since resources are not lost and will be redistributed elsewhere, but you still lose whatever was pruned off. that's a small portion of the biologically-limited vege time lost with an autoflower.
so if you don't cut off much and it shapes the plant better for the light or the space it has to fit, it could easily be a net benefit.
... as long as it doesn't get stunted from an early pruning like that.. i think that'd be the main concern there. if some significant percent turn into runts due to that stress can make it an easy no-go decision.
sever lst could probably do it too, for that matter. piss it off enough and it's triggering early and you get a tiny plant.