We don't live in the same time-zone and this is problematic when you post.
Because more people online == more chance to get up-voted
We all know there are bots here but It doesn't change this fact.
Would it be hard to implement? Actually no as long as you sign the transaction when you save the draft.
#Steemit or Busy could add it
Or I could build a service to do it.
It would be helpful for a lot of people... Myself included