Is it possible to have layers of different pixel size in the same canvas?

For example, I want one layer to be 10x10. The layer needs to remain 10x10 because it’s easier to work with at that scale.
I want another layer to be 100x100 to have fine detail and text since the detail won’t fit in 10x10.
I want the 100x100 layer to overlay the 10x10 layer. When viewing the 100x100 layer, the 10x10 layer is visually stretched so each pixel in the 10x10 appears as a 10x10 pixel square underneath it, but when the 10x10 layer is viewed and edited, it’s still 10x10.

My actual dimensions are different but the problem is the same. I want a fine detail layer over a less detailed layer but for both to have the same size on the canvas. and to be able to edit the less detailed layer without stretching it to a larger size

No, it is not possible.

In the 1.3 beta, you can use Tile Layers to achieve this kind of look, as long as all your larger “pixels” are multiples in size of your smallest pixels. You’d create a Tile Layer with the larger “pixel” size as the tile size, and create tiles that are just solidly coloured with all the colours you’d need. Instead of drawing with the brush, you’d draw with the tiles. You can have Tile Layers of mixed tile sizes within a single document.