This is part of the problem though... If you can choose one of 12 intended lengths, how can it really vary enough based on timing?
For instance press X for "good length", hold R1 for slightly fuller length, if you time the release much too late can it still end up borderline short pitched (as in DBC14)?
There is no need for extra buttons to control length - DBC14 never had those L1/R1 buttons and you could hit any spot on the pitch with just timing, but also mess it up if you lost your rhythm and not hit the length you intended to... Which felt natural and realistic, especially if you turned the HUD helpers off.
Having these L1/R1 buttons is a bad thing imo.