PC-NA : 19 Khajiit and 1 Fishy-cat with fluffy delusions. cp3600
GM of Imperial Gold Reserve trading guild (started in 2017) since 2/2022
Come visit Karth's Glitter Box, Khajiit's home. Fully stocked guild hall done in sleek Khajiit stylings, with Grand Master Stations, Transmute, Scribing, Trial Dummies, etc. Also has 2 full bowling alleys, nightclub, and floating maze over Wrothgar.(Pariah's Pinacle)
There's a bit of history behind the item sets from Hew's Bane and Gold Coast. Those zones were released in Q1 and Q2 2016, prior to ZOS standardizing how set items dropped (which happened with One Tamriel in Q4 2016).
Back when those zones were released, set gear was generally harder to come by throughout the game. The only way to get set gear in Hew's Bane was from doing quests: the story quests and repeatable dailies would reward coffers with gear. (Also, from doing random dungeons, since the random dungeon reward back then was Bahraha and Syvarra, not Willpower/Agility/Endurance.)
Originally, those sets dropped in all 3 armor weights, and in a limited number of traits (Sharp, Precise, Defending for weapons, and Divines, Infused, and Reinforced for armor).
Then came One Tamriel, when ZOS revamped and standardized how gear drops in the game. With One Tamriel, armor was supposed to have just one weight and should drop in all traits and from the usual sources that you're familiar with today: bosses and chests.
The problem here is that the new drop system in One Tamriel tried to shoehorn the all-weights Bahraha and Syvarra sets into the new single-weight standard that they had set up, and they did this by limiting Bahraha to dropping only in light and Syvarra dropping only in medium.
So with One Tamriel there are now two completely separate item pools. There's the original item pool, consisting of all 3 weights and a limited number of traits. And there's the new item pool, consisting of just a single weight and every normal trait. The original drop sources--quest coffers--still reward items from the original item pool, while the new drop sources--bosses and chests--only reward items from the new item pool.
And when item set collection came along years later, ZOS looked at Hew's Bane and said, "Well, it's technically possible to get all three weights for Bahraha and Syvarra, so we'll include all three weights in the collection system." And later, when curation was added, since curation affects only boss drops, it doesn't help with the problem of there being weights that can be obtained only through these legacy quest coffers.
What ZOS should have done was exempt the old Hew's Bane and Gold Coast all-weights sets from One Tamriel's "each set should have only a single weight" rule and allow all three weights to drop from the newly standardized sources of bosses and chests. I.e., these sets should've behaved like Trainee (which was an all-weights set created specifically for One Tamriel).