Installing Hard Vang . . . really hesitant.

[Cmason]

I'm in the process of installing a Garhauer rigid vang and have the mast bracket attached. The mast is 2.2mm and I've drilled and tapped for 1/4-20 screws (yes i have some tefgel). What really bothers me is the boom. Garhauer indicates that it should be drilled/tapped as well but it is only 2mm thick. Am I OK here? If not, I think I'll use rivet nuts but am not sure if I should use aluminum or SS. If aluminum, I assume one would put tefgel on the threads and if SS then tefgel on the body of the rivet nut?? What advice please