The procedures exist and are 'followed', but there's a lot more time-to-market pressure. Manufacturing lines dictate the schedule and software must keep up no matter what.
"We can't satisfy the safety case yet" is all you need to say to get your manager to cave.
If they want to take the risk upon themselves to sign off on a known-unsafe (technically; in practice it was already pretty good, just not good enough yet) device, and go to jail if something goes sideways, they can be my guest...
In practice, they preferred to come back next week and ask if we were done yet.
The project went wayyyy past the deadline, thanks for asking :-)