I run some HC VoS recently to get pieces needed to craft the rings. I must repeat what everyone is saying about it: rng is horrible for any of the drops - excluding maybe gear pieces. So I came up with a solution that hopefully would help those unlucky that just can't get components, gear pieces or shirts/pants from minibosses.
Solution is simple: in place of usual drop from miniboss introduce Vault of Stars Hardcore Box that upon killing miniboss would go directly to the inventory. That box would work similarly to The Knox Box, which players have shown to appriciate while it was on. Contents of the Box would be the following:
Tresshold I (at 10 boxes opened): Sharandar Gear Choice Pack That Pack would contain all the 1525 IL gear pieces that minibosses can drop. Seems to me it would be a good deal, since some people (including myself) just can't get right piece to drop for them. It would be those gear pieces:
Tresshold II (at 25-30 boxes opened): Miniboss Ring Component Choice PackThat would contain all the 3 (not 4, since last boss is not a miniboss) components that are needed to craft Band of Air or Ring of Darkness. Even with farming only 1st miniboss, it still require to run at least 75-90 times in order to get all 3 components, so I think it's pretty balanced. This many runs later some people claimed they still can't get the piece they need so... it should be doable.
Tresshold III (at 40 boxes opened): Sharandar Shirt Choice Pack In that tier I would add all the 1525 IL shirts, such as Shirt of Blinding Offense, since those can drop only from 3rd miniboss. Drop rate alone is terrible, but the fact people has to need/greed (or leader decides) for those is even worse.
Tresshold IV (at 45 boxes opened): Sharandar Pants Choice Pack Same as with shirts - all the 1525 IL pants, but this drop from 2nd and 3rd miniboss as far as I know, so I put it here. And again, drops are just bad, similar problem as with the shirts (need/greed, or leader decides).
Those are the most important items that could drop. Of course it's possible to consider adding some quantity of Shattered Diamonds for example, but with this many runs done people are already fed up with those too. There is also an option to add any of the normal Legendary rings that drop from normal VoS chests, but not sure what tresshold for those it would be (I know, people complained about this too, and I was one of those that got 4 drops with rings that I don't need).
The spaces in between tressholds should be filled with usual drop from minibosses (including all gear pieces, rings components, shirts/pants), so that even with rng it would still be possible to have it dropped in usual way.