The results are not doubtful, unless you need a closed mesh for the shadow that you use.
Take the standard cube create it with soft edges, select a side etc. like I described, you don't need to move anything, the vertices are at the identical position.

It still is a lot of work.
To avoid it, you could switch the shading of. 'Unlit'? I'm not sure about that.
If you baked an ambient occlusion shadow into the model's skin, then it shouldn't be too noticeable, that it isn't shaded.