Re the Daytona pic, is that a butt weld on a casting? OMG scary, should be lap joints. For the Speedtriple break, easily fixed. I would weld a piece of 6mm plate to the back and fully weld. The pillion on a perch fashion of modern things lend themselves to these types of failures.
That's on the engineer's heads. In both cases I would say the design is poor. Aluminium is imported here, again up to management where they source it.