How much has this really been stress tested? I wouldn't recommend anyone use a 3D printed 4B trigger until they've put it through thousands of shots of testing in cold weather as well as warm. I honestly don't think these will last a year.
One full war in 30C heat. They're over 99% solid plastic, and 12mm thick in most structural areas. They're also like $4 in material, so even if they only last a season, that's still decent.