@JCFAX81 can you (or anyone else) explain a bit what are you expecting from a “melodic fill generator”? Is this just about generating random notes in more tracks or something more? I mean, there are apps and plugins out there that make a business out of creating melodies for you. I guess you are not asking for that, but it would be good to set some basic expectations. 
Just yesterday a workaround was mentioned in a another topic: