Sam, a coworker of mine was looking for the same functionality just yesterday. I asked around and got suggestions similar to what you've already received, but then I did some web searching and found this extension/add-on: GitHub - haoliangyu/ares: ArcMap Raster Edit Suite I downloaded it and tested it on a GRID raster I had sitting around, it seemed to work for me. It has a very nice design to its toolbar too, the icons match up with the Esri icons! Is this the functionality you were looking for?
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