Well I think it would be a good idea.
Wait do I really understand what a post scheduler mean?
In my own point of view, I think it means a site that allows you to make so many posts and schedule when u want them posted on steemit automatically right?
If that's what it is then I would continue by saying that it is a good initiative but would poelle really want to make use of it if they have to pay to use it. I would suggest that if be free for some period of time and when it rains traction, you can now request to be paid for.
As for steemauto. I dint know what their plan is though.