This is what Jan Ole wrote in January 2023:
"I would like to reassure you, the latest formula of the Tempera Strings doesn’t break any more. The first generation of the Temperas was indeed a bit delicate in the handling but since then we changed the core and the newer version is extremely stable, they even hold more than an ordinary steel strings. We had 0% breakage so far."
I have the new generation G and its in great condition - just like the rest of the 1,5 years old set. So after heavy use I´ve had only one old G breakage. I wouldn´t worry about the durability
"I would like to reassure you, the latest formula of the Tempera Strings doesn’t break any more. The first generation of the Temperas was indeed a bit delicate in the handling but since then we changed the core and the newer version is extremely stable, they even hold more than an ordinary steel strings. We had 0% breakage so far."
I have the new generation G and its in great condition - just like the rest of the 1,5 years old set. So after heavy use I´ve had only one old G breakage. I wouldn´t worry about the durability