So I found a pretty good solution.
https://www.alphapixel.net/image2plane-2-0-released/
note 2.1 version needed for newer C4D releases - functionally the same.
Which basically import a folder of transparent images to a cloner full of planes which you can then animate through by using the offset slider. and means you can retime the video, reverse, ping pong or even do edits on the fly really quickly in the timeline. Sadly this only works on image sequences not movies but better than the POS image sequence / movie handling native C4D has had for like 15 years. Sort it out Maxon!
Oh the plug in does loads of other nice things - this is just an added bonus.
