This is good if you are a basic user, but 90% of things cannot be streamed part of a subscription. MKV files require 'encoding' which cost 1 point.
In 2018, if your service cannot include MKV part of its streaming service, or even support AVI, then you really need to rethink your business strategy for paid services. MP4 is so old school.
You are more than welcome to contact support and they will resolve all your issues, Streamza has thousands of happy customers