Yeah, to be honest I have read that too but I have never figured this one out - it doesn’t seem to work automatically and no map editing I’ve done seems to allow for this functionality to be unlocked. It would be great if the team or someone had any technical expansion on what that is supposed to mean.
Anyway as for workarounds, in the specific case of percussion, I find it works best to point tremolo to the correct key inside of your percussion map.
So assign the tremolo technique to whatever key triggers the cymbal roll sample you want to use, so whenever the score sees a note with tremolo on that instrument, it will simply play the sample (without the added machine gun effect). I don’t own EW HSO but I just tested it now on CinePerc, it would look like this inside your perc map:
In order to cue different samples based on note length value, this gets a little tricky. Unfortunately percussion maps don’t have the same “conditions” editor that expression maps do (where you can invoke different playback techniques / samples based on note length).
Therefore, the way to achieve that would likely have to be the creation of manual playing and playback techniques, these could be named whatever you want, such as:
roll-short
roll-medium
roll-long
Then, for each one, you’ll have to create a combination technique inside the percussion map to combine them with tremolo - so that when the score has a combination of the roll length you defined, and it sees a tremolo on the note, it will point to the correct sample. When you’ve identified which samples those are, it would look like this in your percussion map:
I forgot that what I had mentioned in the previous post with workarounds might be more relevant to pitched instruments. For example, I like to use tremolos to cue fluttertongue for my woodwinds; however doing so will invariably result in a machine-gun like effect. The way I have discovered to fix this is to manually combine tremolo + fluttertongue in the expression map (just as I did with this cymbal in the perc map), and other times or with certain instruments where that doesn’t work, I have found it helpful to create an empty tremolo switch which basically points to nothing - so that when Dorico sees that in the score, it short circuits the machine gun effect like I said.
But as you can see, the workaround concepts are similar: in short, you gotta fool Dorico so that when it sees Tremolo, it points to your sample. This may take some trial and error but I can confirm it works. Hope that helps!