[chr15m]

It's true, editors can cause a problem if they strip the metadata.

The idea is to only add the metadata as a final step when you export the spritesheet, so at that point there's no need to edit further.

[vunderba]

Yeah. One possibility is you might want to look into possibly developing this concept as a plug-in for something like Aseprite [1]. That's the one I personally use when doing sprite work and it exports a spritesheet and accompanying JSON offset metadata.

[1] - https://www.aseprite.org/