In the end the observations you feed to the model will boil down to a sequentially indexed array, so it isn't too much effort to map indices to hour intervals with a time column. You will have to extend the time column to match the forecasted indices though, but that isn't too much effort at the end of the day.

What do you mean when you say it can't handle hour data? I haven't ran into any issues with it as of yet.

Try googling 'statsmodels predict' and pay attention to which object the .predict() method is called from.

Read the documentation, you are using it incorrectly.

There are teams of people working on and refining this in the mortgage and quantitative finance industries, it is highly unlikely that they would be willing to open source it for competitors to compare notes and take market share.