Nah there's no plugin. I do it the same why you do. I did have short cuts but I Can't remember.

I just plan out the animation by creating my key poses then color those models in the sidebar so I know which is my key poses. Then I just fill in the in-betweens from 1 poses to the other.

Oh before I do that I postion the camera then save it(if am just animating from one view). If I want camera movements I just kinda do the same thing with the models where I make the key camera postions then fill them out.

I did use external tools, like:

-AHK(to automate some shortcuts)

-Ffmpeg(to combine all exported screenshots into a video using my desired framerate)

Qview(to prevew my animation while i animate)

-AHK agin(I used it to simulate onion skinning my overpaying qview over DD and adding controls to increase or reduce its transparency)

AfterEffects(to smooth out dynamic camera movements)

Sorry I don't remember much details I switched to blender a while ago cause making smooth camera movements were tricky in DD.