Copying the sprites to clipboard? That sounds like it might be the same issue as the previously suggested. I don't want a merged image, I want to be able to toggle on and off different checkmark layers that have different meanings, ultimately.
I'll install it to give it a go just in case it does accomplish what I hope.
Edit: Does not work at all for what I am doing. I can load up the "checkmark" just fine. But when I click on the image, it locks me to certain points on the image, not at all where I want to go. I could refine the source image size to directly match the sprites I am overlaying and maybe adjust the tile sizes to make that work, but as is that's a lot of hassle for an end result that I still wouldn't want: it is still creating a "merged layer" -- I can't place these "checkmarks" on their own layer without further advanced manipulation like using XOR or something on a duplicate layer.
I am honestly impressed there isn't a tool created after 15 or so years that just keeps the anchor in place for the clone stamp. That's like 99% of the way to what I want, just needs the 1% change to not move the anchor. These other plugins suggested are huge workarounds. Even a custom brush tool, if it didn't require launching its own miniwindow, could have worked if I could see the layers below. Genuinely curious: does Photoshop even have a feature like this? If not, I am surprised I'd be in such a severe minority of people that could want this that no one has had a desire to develop it.