I get some uneven geometry around the notch edges after applying the boolean modifier to the high poly versions, when smooth shading is on. Hmmm. I’ll come back to that later once I understand more. It looks pretty good with flat shading though.
Low poly notch:
High poly with smooth shading:
High poly with flat shading:
Update: I just discovered the EdgeSplit modifier. That fixed it.
Object data properties tab, Normals, autosmooth tick box also tends to help or marking the edges sharp.
The Edge Split modifier splits, duplicates edges within a mesh, breaking ‘links’ between faces around those split edges.
This modifier can give you problems, like smoothing, the mesh data increases and the object isn’t manifold (suitable for 3D printing). Also unwrapping for image texture can be troublesome.
In your current project, this isn’t a problem. But you should be aware what the edge split modifier does.
Yes I nearly said I have never used that modifier. lol.
Nice thanks for the tip!
Ok, it’s not an ideal tool to use then. Will keep that in mind! Thanks
I used autosmooth instead. Fixed it right up 
