I have an older MBP and while the ML commands work, but take a little long, ~30 sec on 3000x4000 image. ML Denoise works on the current layer, though. I select what I want denoised and drop it on a separate layer and use ML Denoise on that layer. For instance, if I am working on a portrait I select the facial area.
Secondly, ML Denoise results are a little aggressive for me. Unfortunately, ML Denoise doesn't have an adjustment. That were the second layer come in handy. Do ML Denoise on the separate layer, and then adjust the opacity of second layer to get a noice level that works for you.
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