Not enough shortcut for drums scores

There are not enough keyboard shortcut that can be assigned to Drumset.
A to G just cover the basic notation for drums but it is not enough to map everything else.
I find very time consuming for example to write open/close hi-hat, bells, snare cross sticks, power shot.

Why there is such limitation from a technical point of view?
Why we cannot make all letters in the key board available
Please consider adding this feature soon as I think is very limiting
Many thanks
Giaco