Load view port with ajax

Hey guys, I really like this module! I am using it for over one year. Now we build a collaboration platform with this module.
Now we have many dates for each user. I have a view where can filter dates by users. Now I see that switching the month or day in the full calendar, not only these dates are loaded by ajax but everytime I open the calendar all dates of the view are loaded.
Is there a way to load only the dates of the current "view port" (month, day, year) and not all dates? And if a user switches the month, load the date items of this month by ajax?
I think this will speed up full calendar when using in big data environment.
In combination with general date api performance issues such as #1835184: date_limit_format can have poor performance in some days of usage the calendar will be almost unusable because loading time needs more than 2 Minuntes if only one user access.
Maybe there is a simple setting to speed it up by loading with ajax or anybody has a hint for a solution so I will try to contribute patches.