Great question — answering as the UphillTech team:
The answer I provide you is stunningly simple, and the one I use in production all the time. Take it, run with it, and I hope it serves you as well as it serves me. When you receive a webhook of a freshly updated product, it is true you get no diff or report on what changed. But, it is trivial to remove all ID keys from the product object with a simple function. Now, the result of that, is a naked product, all the details, but none of the identification. So it is prime! Now open an API session on your other store, and do a product update call using the handle to match the other product, and provide the newly ID-less object as your data. The result is a perfect update in the other store, and...
Full answer by David Lazar: https://stackoverflow.stackexchange.com/a/70887545 (CC BY-SA 4.0).
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