I got like 6 380s before someone made the shop tracker and proceeded to hawk for like 15 more, against some 300 checks. There would generally be 1 a day sometimes every other day, but I wasn’t always able to log on.
But since the Shrine update I only ever see 379, even going back and looking at my 380s very few would total 379 and not 380. One even has 381 modifiers despite 380 score.
I saw somebody burn 5 million dockets by plugging 380 as the target rating on the brunt’s mod and it never appeared. The devs also confirmed this, seeing the near statistical impossibility.
So I think there won’t be any spicy 550s for a while.