I'm fairly sure I can make a draw-buffer work on the 3DS, but it seems I have a limit of 256x256 pixels due to my ongoing memory issues.
For the Desktop side of the Framework, I typically work with buffers of 1024x1024, so that's a 1/4 scaling thing from the get-go.

On the 3DS Framework, sometimes it uses full sized PC images when they're small enough, whilst other times it refers to smaller 1/4 sized scaled down images.

This is more or less the same issue on the buffer's side of things, and I kinda knew going in that that might be a complication in proceedings.

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The issue now, however, is that because everything is scaled to a smaller buffer, I'm going to need to use an awful lot of scaling methods in order to draw exactly the same images at exactly the same co-ords, on the two different buffers. (PC vs 3DS)

Imagine, if you will, a tilemap of 16x16 sprites being drawn onto the PC's 1024x1024 buffer. That gives me a grid of 64x64 tiles.

If I draw those same tiles on the DS's 256x256 buffer, then I only get a tilemap size of 16x16 tiles. This is less than ideal, given that even a 64x64 tilemap isn't really all that big.

On the other hand, I could scale down the tiles on the 3DS, so that I'm drawing a 64x64 grid of 4x4 pixel tiles over the 256x256 pixel buffer.
But then I'm dealing with 4x4 pixel tiles, and .. Eeek!

Quite where I go from here, I'm not sure, but I'm hopeful that I can figure something out.
If not, I'll just have to draw tilemaps the old fashioned way, and have oodles of sprites all over the place!