mtg card icons Anatomy of a Magic Framed Gallery Pops include an ultra Expansion symbol - MTG Wiki

Unfinity , however, was released in black border with two types of cards in the set: cards that have the acorn symbol are considered casual cards (exactly as if they were a silver-bordered card), and those that dont have the acorn symbol arent, and can be played in sanctioned/competitive formats like Commander, Pauper, Legacy and so on

While this would be questionable in any other tournament if it went explicitly against what the release notes say, I personally wouldn't mind for a set like this, and I think most players partaking in tournaments like that would expect a less serious athmosphere from the beginning, and/or are enjoying more crazyness

What I mean by grand strategy would be a mantra that your deck lives by

A strange adventure with some familiar friends

This synergizes with Rogue archetypes like unblockable effects that make it reliable to trigger the mill while dealing more damage from each attacking Rogue