Hi Jesse,
Are you planning to work on integrating GSAP more tightly into Storyline? I don't see obstacles in doing so, because GSAP is already present, but in some rudimentary way. That way we'll avoid unnecessary hacks and focus our attention to make great courses. CSS integration would be also welcome.
Framer team is much smaller than Articulate, yet there are shipping some great stuff
https://www.framer.com/updates. You can also think about integrating Framer Motion which is probably even better solution than GSAP.
As for Storyline on Mac - you can share this tweet from Josh from Browser Company
https://twitter.com/joshm/status/1785334042558185555 to your stakeholder and what's possible when you shift your focus.
Take care