The prompts that are given to players are entirely controlled by the server side, so I can't affect it. The only actions that a user can do to change the prompt are are skipping the prompt and posting a doodle for the prompt, both of which give just a new prompt somewhat randomly.
On client side it would be possible to record the skipped prompts, so you could see what prompts have you skipped but it would be impossible to try and continue those chains afterwards. Additionally dod hides the public chain id when giving the prompts, so it's not possible to directly find the url of the chain for the prompts either, if you wanted to look at the full chain you have skipped. In the experiment room the client stores the prompt data on a database so it can find the previous step, but it's limited to the experiment room and still doesn't make it possible to choose which chain to continue.
So I don't think that it would be possible to get old/skipped chains in any meaningful way. I think it would be amazing if dod would be updated with an added option for the rooms to let players select which chain they want to continue, but it's not something I can do from the client side.