T1-T2 Bounded mats in Main for what?

Lets be clear here… clearly after lifting from T1 to T2 and jumpling lastly to T3, we’ll be having a lot of excess mats from the previous Tiers… Was there any thread discussion already about this? Wouldn’t it be better if it was Roster bounded?

Since majority of the islands with abundant T1-T2 mats rewards are non-repeatable per char, isn’t it viable to make it Roster Bounded?