Here’s an idea to consider. Check out https://www.cme-pro.com/widi-master/. I know a handful of Ketron owners are using this to allow the music app on the iPad to load the preset they use for the selected song. You can also go the other way. They load a preset and have it bring up the correct sheet music on the iPad.
I’ve also heard that can be down with OAX. I have not tried it myself. Any OAX owners tried it?