Export as & image position

Hi, I thought that Photoshop provides any basic feature and option since it was designed to work with computer graphics but...

Why I can't leave original canvas size and image position? Just export all canvas as it is?

I have some shape in one layer which is smaller than canvas size and want to export this shape separately as svg file, but export tool doesn't have such option just to leave original canvas size and image/shape position on it!

I.e. if my canvas size is 800x800px and there is an icon 400x400px which is not centered (top: 40px, left: 150px) but I really need to save this offset and canvas size after exporting a-a-and Photoshop says: "No. Actually, you can't do this. Set some canvas size for export or just go home, Kevin. Who cares.".

Ok, if I set original canvas dimesions in export options, then it drops image original position and centers it.

For now I have to repair required offset (as in .psd source) for each svg image after exporting. Lol