Our standard test procedures are to test the mini (one setscrew) clamps with negative load normal to seam, and standard (two setscrew) clamps with load parallel to seam. We have performed numerous parallel to seam datum tests on mini clamps and concluded from engineering analysis the mini clamp is (conservatively) obtaining more than ½ the strength of the standard clamps. In fact, the majority of the datum testing indicates the strength of a mini is closer to 2/3 the strength of a standard clamp. In due course, we are adding certified lab testing in this load direction for mini clamps.
In the interim, should certification of the load application parallel to seam be critical to your application, we suggest using the standard (two setscrew) design.