Right, I partially misunderstood your idea. For notifications and such you would need to modify the source code at a deeper level. But for just customizing the home feed (update steam?) changing the theme might be enough.
Ideally there should be a personal ActivityPub instance implementation, something that doesn't require hosting all Mastodon content and can be easily customized in various ways.
Ideally there should be a personal ActivityPub instance implementation, something that doesn't require hosting all Mastodon content and can be easily customized in various ways.