For cancel advantage you need to look at the whole move not just the + frames. For 111 its total is 18 startup, 3 active, 26 recovery.
So in total the move takes 47 frames from startup to finish. If you cancel it, you lose 33 of those frames, so your actual cancel advantage is 47-33 = 14.
Its got +4 frames on hit so you add these here giving you 18 frames of advantage when your 1,1,1 hits and you cancel it into a special move.
Drone: Spawn is 42 frames in total, 1 startup + 41 recovery so if you use this at +18, you can see that you are actually coming out at 18-42= -24 because the drone recovery is so long.
Hopefully this helps but the formula i use here:
(startup+active+recovery) - cancel adv + block/hit adv = cancel frame
Compare cancel frames with the startup+active+recovery of your special move, and you can see where you end up.
Note that with run cancels and stuff i cant figure out what is right and wrong, and also im doubting a lot of the cancel advantage frames we took from the pause menu data, as they dont work out properly.