A leaking weld is a real isue.
Having to cut a slight notch in the K member could have been avoided from milodo (at a price and that would most certainly have ment people would but ***** about that instead) but realy most of us already know about this even thought Milodon could be more clear about it.
Two different aftermarket parts from different manufacturers not fitting perfectly togheter? Thats pretty much what one can expect.