Soft Shackles - release under pressure?

[Paul L]

Any one know of a soft shackle design that allows for release under pressure. I'd like to use one for asym tack and clew, but it would be nice if I could release it while still under load.
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[Bash]

I wouldn't think it would work as well on the tack as a conventional shackle, especially when the release needs to be quick.