Chamfer on a curved surface intersects with other edges

[dony.wiart]

Hi,

I currently am modelling an object, which I want to add rounded corners to. This object is a box with chamfered edges. I would like to create an opening on the front, then round the two top corners.

If I keep the chamfer radius small enough, nothing goes wrong. The only problem is that I find this radius too low, I'd like a bigger effect.

The problem is that I cannot use a large radius, or otherwise the chamfered geometry intersects with the rest.

I think this chamfer problem occurs when trying to use it on a curved surface like I have. So are there any work-arounds? Are there any scripts that can make bevel work for these situations? Or do I need to apply the bevel modifier on my geometry and curve it after?

Thanks.

Edit : I have tried making the opening using a boolean, but it messes up the lighting because of the additional vertices, and I can't figure out how to fix it. I did try removing useless vertices, connecting vertices to rearrange the polygons, but in the end the lighting was still off.