Neither of those options exist natively today.
The integration has services built in to create, update, delete tasks, so it is made to support the quick add and update in the future. That said a proper custom card or dashboard needs to be built to handle it. I believe a few users have built their own custom way of doing it with helpers and buttons, but I don’t think anyone has posted examples.
I have a basic proof of concept custom card I put together in my development environment that is working pretty well, but now needs properly built out for language support, theming, a fuller feature set and determine the best way to integrate into the current ui.
Proof of concept only! - No ETA at this time
Subtasks are a feature request I’ve heard from others too, but nothing actively being worked on at the moment.