I run Harris (have 6 of them) and never have a problem with a solid mount while shooting. That's running 223 up to 338 lapua. I do however like the creativity of making your own. I say push forward and make what you have in mind. You can always dish out the money later if it doesn't work out.

Keep in mind if the legs are adjustable to desing it so you can adjust with one hand, without having to lift the rifle if you want to fine tune it. Also don't use a chinsey set screw design like Harris and others have without the notched legs. It will collapse under heavy guns

I say push forward and keep us updated