Thanks for your reply, @bkelly.
That’s what I thought - the createFileAsset operation’s response doesn’t include an ‘id’, but I thought it was something I was missing.
Would be great if there could be this consistency between responses, so we can hook into the responses easily.
Your idea of Object.keys(o)[0] above was along the lines of something I was actually exploring before I discovered the bulk request, down the bottom of the docs. I’ll revisit this in the meantime, as seems the only solution when using the createFileAsset operation at present.