It turns out there is actually a 2-frame window while 1-1 is loading where you can pause the game before 400 even appears on the timer (when timing starts) and manipulate the frame rule timer so at the end of 1-1 we (at least for TAS which can accelerate perfectly) the game will check for the frame rule 1 frame later for L+R TAS (saving 21 frames - 1 frame delay = 20 frames for a new time of 4:53.700 from 4:54.032) and 5 frames later for no L+R TAS which loses 2 frames on each fast accel in the first and third room of 1-1 so the no L+R TAS can only save 16 frames from this trick (21 frames - 5 frame delay = 16 frames for a new time of 4:53.999 from 4:54.265). In theory, this is JUST what we NEED to break the infallible 4:53-second barrier but we need an SMB1 game/rom that won't freeze frame rules when the game is paused, which the ROM I have does.