I totally get the concern, Yuko. I’m not thrilled with the additional cost of using Sonic Sage, but I’m not quite ready to dismiss it.
I think the possibility to move off of OpenAI ( or bundle with your Plex Pass and manage in Plex, as you seem to suggest ) is a realistic option. Whether or not the Plex team decides to do that probably depends on how many folks are using the feature in its current state.
To me, Sonic Sage feels like a beta for things to come.