As the rewards here are permanent and not time-limited, you can chip away at them at your leisure
The problem with the aftermath cycle is that the most common pairing of effects is low-tier uncommon plus common, and in some cases (Prepare // Fight), common plus common
Ideally youd like to pass this between yourself and another player, but I could see games where your opponents just play keep away with your commander for much of the game while drawing a bunch of extra cards, which seems like a pretty big downside that you could mitigate to some degree with cards like Homeward Path and Sword of Hearth and Home
According to the official Pokemon website, the promotion will only be running for "a limited time" - while this is obvious, "limited time" usually isn't too long
11 Jynx ex Loaded with two attacks, Jynx ex might seem solid but takes too long to set up and can be easily disrupted