I believe other than what I'd already mentioned, no- nothing extra unless they update it. I recently got a new PC and had to restart from a new game and I'm thinking of adding a full 4/20 guide to this post as I've realised more things in attempting to complete 4/20 mode again.
I want to keep the main guide up as it works for Nights 1 through 6 but definitely not 4/20. I only now get how lucky I was to beat it originally.
I think the way I was doing it would work. That is, ignoring the monitors completely and just listening. That way you can save precious power, since the only thing the monitors will do is let you know what rooms they're in. All you really need to know is when they're outside your doors, which you can do just by listening. That also works for Freddy, as she won't appear at your door until after she giggles at least three times. After her 3rd giggle, I'll check the room by my door and if she isn't there I'll wait until she giggles again to check, but I never leave the tablet up longer than a second as I just need to check to see if she's there.
As for Foxy, I keep my mouse hovering over the left door button at all times. That way, as soon as I hear her running down the hall I can close it, wait until she bangs on the door three times, then after a second I can open it again.
It's difficult, but doable.
