Daniel, I tried those EW Hollywood Strings Expression maps downloaded from your Steinberg website. These maps are generated prior to your admission to Steinberg. I tried and found an issue that Dorico 1.1 writes insufficient MIDI data to the exported MIDI file for any MIDI instrument track in a Dorico file that uses certain expression maps of those I used above. Such exported MIDI file, if you open that, you could see that it has lack of certain tracks of what I said above. I am afraid that you guys may want to perform a thorough test to those old expression maps on Steinberg website to check compatibility issues with Dorico.
P.S.: I also tried VST Expression maps of Vienna Special Collecions Volume I (fetched from VSL website) and found its piano expression map could cause exactly the same issue as well. Fortunately I suddenly realised that I don’t need a specific expression map in Dorico for piano.