"Trading" system is wildly broken and completely unnecessarily expensive
At this point, "trading" is a misnomer as it's actually just a way to further restrict the card economy and consume high-rarity cards to reduce the pool available for trading.
You get 25 tokens per ♦♦♦ card you consume, 125 per ♦♦♦♦, 100 per ⭐, 300 per ⭐⭐ or ⭐⭐⭐, and 1500 per 👑 card.
You can't even trade anything above ⭐ so you are literally destroying irreplaceable, untradable cards if you consume anything above that rarity, but realistically it's the most efficient way to obtain trade tokens.
HOWEVER, you can't consume your cards unless you have at least 3 of them because, like flair, it won't let you convert the card unless you have more than the 2 you need for a playset. So, in reality, you are SEVERELY restricted in the cards you can consume and, more than likely, you will have to consume dozens if not hundreds of ♦♦♦ cards in order to trade just a few of the higher rarity.
This doesn't even touch on the fact that you need 120 tokens to trade for a ♦♦♦, 500 for a ♦♦♦♦, and 400 for a ⭐ when the ⭐ cards are harder to get and do less for your gameplay because they are all just alternate arts of non-ex cards, while the ♦♦♦♦ cards which are all ex are easier to get in packs but harder to trade for because you need more resources.
I don't understand how any of this makes sense to enable "trading" but I will likely not be using this feature AT ALL as I already own all of the ♦ and ♦♦ cards, which are the only ones you can trade for free, and I have no desire to jump through all the hoops necessary and burn large swathes of my collection to trade the cards at higher rarities.