"Stretch- bolts" have been common in the UK motor-trade for~20 years!
When the first engines appeared with them, we assumed it was a racket to sell more parts
Up until their introduction, it had been normal to torque in stages and sometimes time-lapses between stages.....sometimes run to working -temp amd retorque hot, others cool and retorque .still others nail them down and send 'em out.
then came stretch bolts.... low initial torque , then mark all heads with a paint-stripe, then wind each one so many degrees in diffferent stages.....you'd feel them "twang!"..It needed a bit of research , (easy, nowadays with the internet.) A much more accurate way to tighten, as it virtually eliminates the problems caused by burred/damaged/dirty threads.