Cancel individual frames in an animation

We had an incident yesterday where we had 400 or so frames up on Chaos Cloud and we noticed that there were a handful of frames that had errors which we needed to fix and re-render. Where as the rest of the frames were OK to carry on rendering.

Whilst we could have stopped, cloned the job and set a new frame range to remove the unwanted ones. The frames that were actually OK were already part way through rendering, some almost complete and we would have lost that progress starting a new clone job. If we could simply select particular frames and say don't render and allow the rest to carry on, it would avoided having to restart those frames.

Or another option would be to able to clone the job and if the frames that we select in the frame range are currently rendering, they carry on rendering in the new job rather than restarting.