A properly made soft shackle will be stronger than a single loop. For reasons that I don't understand, a rigger would call a simple spliced loop of line a "gasket."

For making soft shackles this method is a bit more complex than what you usually see documented on the method to make these, but is proven stronger:  Brion Toss Soft Shackle

A soft shackle carries the load across FOUR legs of line, while the loop only has two. If the loop has a 100% perfect splice, the maximum strength it can have is 2X the strength of the single line.  A well made soft shackle is theoretically 4X the line strength, but realistically tests out to 3X.  

Given the pretty amazing breaking strengths of well made Dyneema line, this is really impressive. A 1/4" (~6mm)  Dyneema line has a breaking strength of 8600lbs (3900kg), which means a well made soft shackle made from that would have a breaking strength of almost 26,000lbs (11,700kg), much stronger than any stainless shackle you might consider using.  Two of those could lift your boat out of the water. More than suitable for pretty much ANY application on your boat.

Bill Kinney
SM160, Harmonie
Hollywood, FL