The difference in data models and APIs, combined with the amount of features Apollo supported would likely make it a fairly large task.

But that aside, he mentioned in an article recently that he doesn’t have an appetite to pivot the app towards Lemmy or another third party: https://www.theverge.com/2023/6/13/23759180/reddit-protest-private-apollo-christian-selig-subreddit

Having feature-rich apps that provide good user experiences will also be vital. Mlem and Jerboa are both open source, and could likely use contributors