Firstly, I am a newbie when it comes to video editing, especially Kdenlive. So sorry for any mistakes in terminology etc.

I am using Kdenlive 16.12.2 on Kubuntu 16.04.

I have been experimenting with rotoscoping and it works really well for me, but there are a couple of minor issues that I want to check if there are workarounds for.

1. In the manual it suggests that additional matte control points can be added by left-clicking on an existing line and removed by right-clicking. However, neither of these seem to work for me.
2. I have inserted keyframes where the matte should change shape and this works really well. However, when frame stepping forwards and backwards using the left and right cursor keys the matte seems to loose sync with the video. In fact the matte appears to step okay, but the video doesn't always update behind it. This makes it difficult to fine-tune the matte movement to match the live action.

Thank you for any suggestions!

As for adding/removing control points, the manual is probably out-dated since this feature has been partially rewritten. I'm not entirely sure there is currently a way to do this, maybe double-click ? I'd have to check that

As for the sync issue, it might be a problem of video codec. h264 is not that great for single frame stepping, especially if you don't have a lot of I-frames.
Other possibility: the FPS of the source video is not matching your project's FPS. You can check that in Project->Project Settings to see what FPS your project is using, and View->clip properties to check what is the fps of your clip.

Good luck