Me : I don't see a problem with asking additional questions if needed. However, I do see a problem with running a 2nd referendum without a mandate. There are legitimate questions that could be asked e.g. ...
Do you wish to
a) Accept May's deal (deal)
b) Reject May's deal (no deal)
You could additionally ask (if you want to create a mandate for a 2nd referendum)
If the UK reject May's deal, do you wish to
a) Leave with no deal.
b) Rerun the first referendum.
Me : No. You can't run a 2nd referendum without a mandate and there is no mandate. You either need a general election or permission from the electorate to re-run it or you decide to ignore democracy.