I am once again asking for something to do with rare duplicates.
Apologies for reiterating this topic, but with the added shiny rares which don't seem to be wonder pickable and likely won't be able to be traded, I feel it is appropriate to again state the desire for some sort of pity system/ duplicate protection.
In Hearthstone duplicates can be converted to dust at roughly 1/4 the value so for epic and legendary cards any 4 epics/ legendary cards can craft another of the corresponding rarity, and feasibly with enough commons they could craft higher rarity cards. Magic Arena also has wildcards that can be exchanged for cards of the corresponding rarity.
While neither Hearthstone nor Magic Arena allow trading, neither does Pokemon TCG Pocket for rarity above one star. The flairs for cards are hardly noticeable, and for high value cards many of the flairs only work in a battle and can't even be appreciated in binder or display boards, and exchanging high rarity cards for trade tokens doesn't make sense as the rates are bad and people with many duplicates of high rarity cards likely have all the cards they could trade for already. There's also not much in the premium shop either, so there's no incentive to convert cards to special shop tickets after everything has been purchased that can be with them.
In my opinion the ability to cash in cards for roughly 20%~25% of the pack points it would take to exchange for them seems to be in line with other similar games, and would also be roughly in line with the rates other cards are traded for.