One of the issues that appears very common here is people leaving/surrendering in career mode. While the ability to surrender is an important part of the game, particularly salty players abuse this mechanic in order to deny their opponent ink. With this in mind, I feel that a rework to the rewards system could be in order. The simplist way I could think to mitigate the issue would be to allow players to wager ink or coins as they set up a match. This would deter leavers and allow players to accumulate currency for now decks more quickly.
An additional note. I am unsure of the accuracy of this but stall decks generally feel like they output less ink than traditional decks. My guess is that this stems from the longer games and fewer prize cards taken. While I may be completely wrong, rewarding the winning player for the number of cards their opponent drew could reward stall players for surviving 20-30 turns of attacks.