Planned and has been planned pretty much since the beginning. I am well familiar with how much time gets wasted when using tilesets like Castle or Carrotus.

In other news, animated tile editing is going pretty strong. You can clone and delete animations, add flipped or animated tiles as frames, and associate events with animated tiles just like with regular tiles. (I've tried making entire animated tiles translucent, as opposed to just their individual frames, but unfortunately that has no effect in JJ2.) Still a number of issues to work out, though, including making sure you can't embed an animated tile within itself and trigger a stack overflow error. Also selecting a generator event works properly now, and 1.00 translucency support is almost done.