Yes I already know, it would require a lot of resources to allow real-time updates. But I think it can be limited.
And I already know that you can push data to Klipfolio api to achieve real time, but that is not always possible to do from the source.
My proposal is to allow 1 RESTful web service data-source per customer that is on a constant loop. It would do the RESTful request, and as soon as it gets the response back from the server it will do it again. Constantly looping the same request over and over again.
Allowing live updates for only 1 data-source would hopefully limit the overhead usages of resources.