I use a custom percussion kit in my film scoring template that contains every standard perc. instrument I may need in a cue.
The new Instrument List token in Dorico 6 is an excellent start to providing an automatic percussion legend under the part name for my percussion parts.
However, what would make it even faster and more accurate would be the inclusion of a Sounding Instruments text token. That way, only the instruments that were used in that flow show up under the part name.