I've been lucky enough to join the Apple workshop in Amsterdam to prepare RocketSim for macOS Tahoe. Last week, I've visited Amsterdam for three days and made great progress on RocketSim's UI.
Apart from updating the app icon, I've also spent time on revisiting existing user interface elements. A few custom components were ready to be replaced by system components and the new glass background truly makes the UI more part of the system:
If you have the chance to join any of Apple's workshops around the world, I'd highly recommend doing so. I've been able to sit down with an Apple Designer, who gave me dedicated feedback right away. I could even check-in multiple times during the workshop to revisit decisions. Altogether, it's a unique opportunity to set yourself up for success when the new OS updates become generally available.
At anytime, visit the Meet with Apple page to see if there's a workshop you can attend. Good luck!