A lot of good info here!
As a Machinist that has worked in the electronic cabinet industry (thin metals) and knowing rigging
and for a shear application I'd go with drilling and tapping with a fine threaded tap. And go with the shortest screws possible, not allowing more then a couple threads sticking thru to the other side.
Also drill one size smaller then the chart recommends. The charts
are for 75-80% thread. A smaller hole will give you 100% thread. In aluminum
every little bit helps. Be sure to use a wax or thick grease when drilling and taping
. Alum. tends to gall when it get hot.
Over time if the threads wear out then you could go with Rivnuts or rivets. IMO Rivnuts would be for something you plan to take off and on a few times, expensive too. But still use the TefGel whatever you decide!