You won't be #1 unless you use pinball.
Granted some scores you might not be #1 unless you used prenerf flame notes. But definitely not all of them. For instance, you couldn't get 300k on Charlene with prenerf flame notes.
Juggling 2+ lanes is not button mashing.
However juggling 2 lanes can be done by button mashing.
Difference is that one method rewards you with Blitz mode points while the other doesn't.
The exploit in question here is when juggling lanes with flame notes while button mashing not when legitimately juggling 2 lanes properly.
Juggling lanes is important no matter what load out you use.