How about redoing the star rating of ascension materials to be 1 - 5*? 1 and 2* are unchanged. 3* represents only farmable current 3* items. 4* represents what was previously 3* unfarmable items. 5* represents what was previously 4* items.
- The star ratings of heroes would match the star rating of ascension materials required to take them to their maximum tier.
- The star rating of ascension items would match their rarity
Click for caveat
Yes, when there is an opportunity to get a 3* unfarmable ascension item, the chance of getting unfarmable and farmable items is the same. However, there are far more opportunities to get farmable items, thus making the rarity of farmable versus unfarmable items for the player very different. Star ratings should reflect rarity of items for the player, not the devs.
This is a relatively minor quality of life improvement, but I think it makes a lot of sense compared to the current scheme. When I started playing I had no idea that some 3* ascension items are a lot more valuable than other 3* ascension items.
Since farmable and unfarmable 3* items are already treated differently, I think the work involved for the devs would be extremely minor.