I agree with your reasoning and wish it was possible. Cutting out that section and welding in a filler panel isn't the problem - but metal working the weld seam is. You can't get a dolly behind it to stretch the weld areas to make the section flat (like we did on the Challenger fenders). You would end up needing to fill the lows with some sort of filler. We were able to remove the inner structure/brace on the fenders to hammer/dolly the weld seam. When we do a patch panel (marker lights, sail panel seams,etc), we cut the panel so that the patch piece fits perfectly into the opening. Even with a tight no-gap tig-welded seam, the panel will "wad" up and need to be worked flat.
Have you looked at maybe romoving the inner bacing enough to have access ? it would be easy replacing the inner turret bracing as you could cut from access hole to access hole on the structure side, know what i mean ?
This would give you enough room to hammer the section as you weld....... Just throwing some options your way as the whole body would look even better totally smooth