First, gorgeous work on that bag!
Unfortunately, I’m not sure that this is true just yet… though I do hope that it will be a viable option once they reintroduce the super low power engraves that we saw (ever so briefly) a couple of months back. Here are a couple of examples of my experiments with the technique you’re describing using a pre-release unit - as you can see, the results were less than ideal using the current settings, but another forum user showed their results with that technique using a different laser cutter. Their results suggest that it should be possible once we get those low power engraves back.