I've had no issues. I sometimes mount/dismount by standing on the pegs with the bike on the stand, with no signs of stress or damage. I don't have any concerns about it, since it's now physically impossible to crack the case with the stand, and if anything at all is damaged it's just the bracket.
The chamfer is not as deep as it looks in the picture. I didn't leave 1/2 the material, but there is a noticeable vertical portion of the hole left. I just went deep enough to make the bolt heads flush, which is required for this mod to fit. Also, since I just used a handheld die grinder, I intentionally went deeper in the center than I needed to, in order to get the contact area out where the hole was wider. If you have the right tool to make the chamfer, it would be better.