Honestly? I'd rather initial dash, crouch to cancel it, then fsmash. It's faster and easier to use.
It's not nearly as flashy though.
why do you cancel it, its not slow on its own to just dash and than just wait for the animation to end and then f smash.
also, something that i have been putting into my game with great effect is grab releases and jabs
there are a lot of characters that dont slide out of jab range when you grab release them from a regular grab. and after the jabs you can either jab cancel the second jab into more jabs or just do a running grab. shield/roll will always be faster than lucarios jab, but most people are too flustered to think of that and either wont do anything fast enough to get out of the jab or will do something that gets outranged by the jab.
unfortunately since this isnt gauranteed, it will only work on most players at the most 4 grabs in a row. but when the opponent is over 100% and with lucarios stupidly fast pummel 4 grabs, 4 double jabs and a throw can mean some pretty massive damage
nobody that ive seen does this, and i dont expect anybody to in the future, so ima call it the KG combo lol
also, on heavy characters and fast fallers, i think the best way to rack damage is to mix and match the established methods that you already have. the FP can be broken out of, up tilts can be DId and up throws do crap damage. So if you have a spacie you can do something like...
up throw, up tilt, jab, up throw, up tilt, FP, FP, grab, pummel, jab, regrab, f/d/b throw
or if you have somebody like d3,
up tilt, FP, FP, up throw, up tilt, up tilt, fair, fast fall, run behind them and pivot grab, pummel, double jab cancel, double jab, grab, pummel fox trot backwards, f smash.
now these arent established comboes but they are just examples of the kind of pressure based mindgames you can put on people by mixing and match the different low KB moves you have for a lot of damage
thats the kind of stuff i do and it works pretty well so... idk