Hello! Panthera has pretty good integration via Editor Scripts.
Also, there is Panthera 2.0. Not sure if you’re talking about this one or the first web version. You can check it here: Panthera 2.0 - Animation Runtime & Editor
Panthera is not a bone editor. it’s just a timeline with full property and event manipulation, like any other timeline sequencer in other engines.
You can create and open animations from the Defold Editor with one click.