Another concern: let's say the most new-battle-mage-friendly format is called Frontier.

Meanwhile, the "the farthest most limits of knowledge and achievement" is Champion League Modern or Wild format (depending on your perspective).

So you might start in Frontier format and then move to the frontier formats.

Because the primary definition of frontier here is "the farthest most limits of knowledge and achievement."

Other definitions?

"a border between two countries" or "a line of division between different or opposed things" -- lorewise, we can't say it's a border/line/division between traditional TCG and Web3 TCGs, because those don't exist in-world, and the Order of the Scale, which runs the Arena Games, wouldn't use this as a reason to name their latest format.

"a new field for exploitative or developmental activity" -- obviously this isn't a format where fledgling battle mages are exploited. But it could be a format for developmental activity. As long as that happened IRL (i.e. introducing achievements, glamours, missions, quests, etc. here first), we would have an in-world justification for the name, as the Order of the Scale experimented with new concepts to spice up the Arena Games, and that's what we'd focus the format's lore on.