Can I cut here? (QA1 upper control arm issue)

I spent a few hours getting the QA1 UCAs installed. The driver's side seems ok but on the passenger side, there's a piece of sheet metal that interferes with the travel of the control arm.

I can't see how I could have screwed up the installation so is this just a case of "extra" sheet metal from Detroit or is the arm not designed correctly?

In either case, should I take the cutting wheel to that metal to provide the clearance?

Could that weaken the mounting point?

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