More leaves means more growth all around so long as your roots can support it all.. Earlier when I said I'd chop that pH troubled plant and let the secondaries take over, I didn't mention that it would be turning back the clock for the sake of a fresh start with new lush foliage (pretty much revegging).. Once flowering begins though, the clock can't be tinkered with, so you let them keep any foliage you possibly can because they are on a 'deadline'..
Personally I'd only bother nursing a plant to sustain genetics if it came down to it.. I prefered small plants, so I always took far more clones than I needed, and vegged out more than I needed, selected for best roots popping, and culled what I couldn't flower.. Squeaky wheels got no grease in my grow room..