The issue of Starline focusing on more popular calibers is odd.
The recent run of .480 brass sold out in something like 3 days? I have no idea how many pieces are in a typical production run but If a 3 day sellout isn't an indicator of need and popularity I am mystified what other metric would qualify as popular.
When they had everything in stock back in the day, they probably sold 20000 pieces of 44mag for every 480 Ruger case. I'd wager that even the 500 S&W Mag is more popular than our pet 480.