I feel like this is a counterproductive way to deal with a handful of disconnected symptoms of other unrelated issues.

In the case of a player with unlimited resources, of course you want them to level their cards instead of hoarding bcx 1. What about those who are grinding though? Maybe they play in gold, but they're happy with level 4 on that common for now because they're clever and pay attention to the stats. They'd rather devote those resources elsewhere and get more cards that will again take them months to level. If they can win, why wouldn't they be entitled to full rewards? Why does a reward pool need to be unnecessarily complicated?

This potentially limits the way players can play without being punished by the system, so I'm against it. I think it unlikely it'll be allowed to fail though, so idk why we are doing this.