As a player, you can choose to use these items to trade them with other players and obtain what you need
It's also shown off some additional spoilers (one for each deck), a new token type, some sweet lands, and a cool Pip-Boy card frame
However, in most cases, a 40-card deck will provide more consistency in drawing your best cards, and I would prefer that over a diluted 60-card configuration
In this kind of deck this is about as close to Ancestral Recall as you can get
Incapsula incident ID: 1007000060042216240-8354548975337895
There are also artifacts such as Contagion Clasp and Contagion Engine for repeated proliferate triggers, as well as Karn's Bastion for another source of repeated proliferates