This isn’t supported by Lemmy yet. It would be relatively easy to let our users follow other users on the client-side, and show your followed users on the subscriptions page. However, as this isn’t supported by Lemmy, your followed users unfortunately wouldn’t sync with the web app or other clients.
It would get a little more tricky to show notifications when a user posts, or create a “followed” feed that only shows posts from users you follow. To do either of these, we’d have to make a separate API request for each user that you follow. If you follow a large number of users, this could be problematic.
One potential way to mitigate this would be to have a separate “send notifications” option for followed users, and we’d only allow you to enable this setting for ~5 users.
I think this is a cool idea. Following users isn’t on our immediate roadmap, but it’s something we could look into in future.