I had an implementation of fetchMoreData working in my custom visual back in the 1.x API, but this seemed to break when 2.1 came out and left the feature turned off as a result. Another recent thread inspired me to give this a go in version 2.3. I'm now working on 2.5 but the problem seems to be the same across both versions with a 2 million row dataset.
Back when this first got implemented, I recall the developer visual not working correctly with this method and it had to be tested in Desktop, which worked fine back in 1.13 but I'm now verifying the code and the problem is the other way around - the pattern works fine in the developer visual and loads all 2M rows but just sits there doing nothing in Desktop if I package the visual - it loads the first 30K rows but then doesn't progress any further.
I'm not sure if it's specifically fetchMoreData causing the problems, but if I cap the visual datset to < 30K rows so it doesn't hit this function then it will render successfully... so I'm just looking to investigate this a bit more before I consider submitting a new version of my visual with these changes.
I hadn't tried the service test with the packaged visual, so thanks for suggesting. It works as expected in the Service, so looks like it's possibly not something to do with the packaging process and seems specific to Desktop.
I'll follow-up through the email channel - I'll put together a .pbix with the compiled code and a 100K row dataset and there's a branch of the source code that I can provide you with a link to through there as well.