my upper control arm mod..

Nice work, looks like it'll cost less than a wedge kit .

I put a brace under our arms with the same mod. The arms I see with a mod like yours at the track have a brace under the arm and/or a tab/plate welded in place over the cut. You could put it on the inside if you didn't want it to show. I didn't want our brace to show so I put it inside the arm, rather than across the bottom. If you don't race the car and check the welds every now and then you should be OK with what you have.

John