The 124 KSI strap will have less elongation than the 80 KSI
strap and will therefore take more of the applied load, with the
combination failing much closer to the 124 KSI figure than the
collective 204 KSI limit. When the 124 strap fails, the 80 strap will
stretch and fail almost instantly.
That's how I'd see it, anyway.

Dan