I looked into those and couldn’t find anything suitable. This is a pretty big box:

https://www.doorbird.com/downloads/datasheet_a1071_it.pd

It’s expensive, not weatherproof, and hard to order. Same for the one made by 2N. These both recycle old DSL technology I believe.

How difficult it is to install also depends on how your doorbell circuit is wired. Mine goes from a transformer in my basement to a switch on my door and from there to two chimes with a junction hidden somewhere. For these converters to work you need a straight run end to end.

That may be slightly better, but you still need to pull a connection to the chime. In my case, it wouldn’t be all that much easier to get there vs going straight to the door.