I haven't and I won't. As much as I hate the API changes and as much as I hate being forced to use the terrible official app, there are communities on Reddit that won't be going dark indefinitely that I am an active part of and wish to remain part of.
Lemmy is a great concept in theory, but in practice it leads to what was a single community on Reddit being spread over several instances. A community with tens of thousands on Reddit might find a few communities spread over a handful of instances and because a community doesn't show up in the Communities list under All until someone does the [email protected] command for that specific community (meaning they physically went to other instances to find that community on that other instance and then in practice manually added it to the list)
This also means that as the amount of instances grows, specific communities will become even harder to find as the instances themselves become more obscure and hard to find.