I was looking up what the coast guard's rules are, and came across this article:
https://cruiseradio.net/cruise-ship-muster-drill-changes-2023/
In the article it quotes Royal:
Greg Prudy, vice president: “
We’re always open to change,” he said, “but we’re not so open to going backward. So we will always look for moving forward and doing things if they’re better… for our guests and our crew.”
He added that they were seeing a higher percentage of compliance with the new format than they’d had with traditional mustering.
And Carnival:
“
Our implementation has also received very positive feedback from the U.S. Coast Guard and other safety experts, as well as generated positive comments for effectiveness from our guests during our post-cruise survey results,” Chiamis says. As a result, “We will continue to utilize our e-mustering process while always looking for ways to improve its effectiveness.”
The article also says that when Norwegian went back to traditional, it 'coincided' with cutting back their entertainment crew, but claiming safety was the issue.
IF we go by that this is indeed about safety and compliance, what do Royal and Carnival do different?