I’m currently exploring EPUB3 functionalities, particularly focusing on JavaScript interactivity within e-books. However, I’m encountering inconsistencies across different e-readers. For instance, some functionalities that work in the Thorium reader may not work in Apple Books on macOS.

What would be the best approach to determine which JavaScript functionalities are supported on different e-reader platforms? Should I prioritize specific e-readers or aim for broader compatibility? Additionally, is there a reliable method to test JavaScript functionalities across various e-readers?

Any guidance on how to ensure JavaScript interactivity in EPUB3 e-books functions consistently across multiple platforms would be greatly appreciated. Thank you!