Ok so if I presume that the fuzzboobs 4/20 mode is the same for FNAF 4/20 mode, and if they have the same movement opportunity with FNAF 4/20, than here are a few tips on how to beat 4/20, you should count Freddy's laugh if she makes six laughs in a row that means she's near your door and you can see her at cam4b and btw you can stall foxy (I think) without ever going to her camera (as long as you open the camera she will be stalled, same goes for Freddy but you need to be at her camera cam4b) but if you want to check what stage she is, make sure to look at ur doors, you need to close the right door (where Freddy is) and check the left light/door if Bonnie is there, if she is there close the door and you can check what stage foxy is (cam1c), than immediately return to cam4b and you can check if Bonnie is gone or not
All the other cameras don't matter only cam1c and cam4b
And be sure to open and than the close the camera as fast as possible, to distract Freddy, while also checking the lights each camera flip,
But I'm not too sure though be sure to correct me if I am wrong in any of these