Non-programmer here trying to grok the under-the-hood things that make the app go vroom… 
QT 5.12 is in beta as of today, and I’m wondering if the new version will address the specific font issues that are holding Dorico back from being fully compatible with macOS 10.14? Thanks.
This says it’s fixed in the beta version: [QTBUG-69955] Fonts display with incorrect weights in macOS 10.14 Mojave - Qt Bug Tracker
The planned QT 5.12 final release date is 29 November, so I don’t suppose there will be a Dorico fix before then - you can’t really release a “production” version of something (Dorico) that depends on a “beta” version of something else (Qt). There are a lot more changes to the QT beta than just that bug fix, and some of them might break something else in Dorico, so they need checking out. Qt 5.12 Release - Qt Wiki
We have back-ported the fix for QTBUG-69955 to Qt 5.11 and are in the process of qualifying a release. All being well, there will be a new build of Dorico that has a fix for the two font issues available soon, hopefully within the next week.
Glad to hear it!