Is the dataset items synthetic event billing handled internally on Apify's side or I can tweak the SDK & override the pushData () and pass a dummy, non-existent event name to bypass its billing?

What's your use case for this? It's an optional item so if you don't want it, you don't have to use it.

I prefer to keep the specific use case private for now, but the idea is that I still want to use pushData() while having the option not to bill for it. I'm looking for the smallest possible scope change and want to avoid using a custom event for many obvious reasons ..

Thanks - that's helpful context. I'll ask if this is possible.