Thanks for your reply!
Here’s the score and the diagnostic files:
Also sprach Zarathustra (reduced).dorico (2.1 MB)
Dorico Diagnostics.zip (2.0 MB)
With the brass it’s 7 MB so I made a copy with just the woodwinds. It’s just Strauss, so no need to obfuscate 
Among other things, I’ve been copying it as a project to figure out how to use Dorico. As you can see, I’ve been mostly successful, though I’m finding that there are a few things that require hacky and buggy workarounds, most notably the 3/2=9/4 substitute meters. There are a lot of annoying side effects every time I insert the “pickup measure” workaround (yes, it’s a workaround, not a solution) in the next part that needs it–but I digress…
I’m not sure about the libraries and such, but I haven’t messed with much aside from a few notation/engraving behaviors (like whether to use dotted rests and where to use ties, etc.). I have been using the full Iconica Sketch et al. playback template, though I had to manually set up the e-flat clarinet (on the HSO clarinet, which has much more of the needed range; Strauss really pushes every instrument to its maximum…) and also the organ (I used the ARIA player because its Hauptwerk isn’t as offensive on the opening pedal; I do wish there was support for dynamics on the organ…), which isn’t in the reduced sample. I did set it to Silent for the upload, and I didn’t see any improvement. After doing that, I restarted Dorico and it may have helped a tiny bit, but not much.
Let me know if you need any more info.