Keeping a record is a good idea.
I dunno about 48 hours of darkness. What would that simulate, from the plants' perspective? A total eclipse that lasted a really long time? I kinda think that would stress them, but who knows. I try and give them as close to what they would experience in Nature as possible... except an ideal version of it. Perfect weather for growing nice and big and healthy, just enough water, natural lighting, etc. Maybe instead of going right from 4 hours of dark to 12, creep it up by 2 hours every few nights? So the flip would happen over a couple weeks, instead of instantaneously. We are trying to emulate a change from spring/summer to summer/fall growing, which happens gradually and not overnight. Something to look into anyway. I've done things that way and felt it went quite well, but I too need more data to be sure.