There are a lot's information in your message. As you are talking about ipad I am guessing you are using Cuety?
If so you would not be able to use the fixture file I made previously as the file is for cuelux and also because your dimmer pack use sub-fixtures for each channel, but cuety do not manage sub-fixtures.
So the best would be to patch 4 1 ch dimmer from the generic manufacturer.
About the fact that you can only do on/off I thinks it depends on the way you set up your dimmer pack. IT can act as a switch pack ( current behavior you have) or a dimmer pack.
I hope this will help you,