Hairpin Tremolos

I am currently working on a piece that uses a lot of tremolos with hairpins (in this case going up and back <>).
I am using Note Performer for playback but I am not getting any results from the dynamics. No swell and retreat.
Is there some trick for getting this to playback properly? CC automation?

It does work, but the effect may be more subtle than you anticipated. Try to increase the dynamic curve in Playback Options/Dynamics …

Ah, there is an issue here. Hairpins do not playback without explicit dynamic markings on both sides, a fair amount of conventional markings do not send playback information, such as: <> or ><

This means standard literature from Beethoven to Ravel needs excessive twiddling to get playback results (probably automating CC7 - gross!).
Try writing a sustained note with a swell and retreat playback and you’ll find it’s impossible.

Or you could add the concluding dynamic marks and then hide them.
(As you can probably tell, I am trying to avoid drawing in CC curves, but then someone with more DAW experience might find that a much simpler solution–which I will likely have to learn to do more readily as Dorico adds more DAW-like capabilities.)

well, they do for me.
I exported these bars as midi:
and here is a graphical rendition of the CC11 data (NP expression controller):

It’s not working for me. Here are two versions, one with and one without the explicit dynamic markings.

Anybody else? I can’t a get a basic drum roll swell from dorico playback.

It does work in general, e.g. the attached project will play back using the default HSO sounds. (1.42 MB)