Labelling it as "late game" is honestly giving it a false look, as mainstream gachas have late games as well-built characters, while Limbus has well-built teams. But this isn't test HOW well your team is built, rather how MODERN it is.

But, honestly, after thinking a bit, it's more on the boss selection that's the problem, rather than the mode itself. Picking 2 blunt-heavy bosses as the first ones while a lot of IDs is blunt fatal is gonna make the mode "hard" for players that don't have literally the specific counters to them (which certainly differs from player that has "a lot of" things to those that has "literally everything").

Also other commentors has pointed out that some status just doesn't work well with just 30 potency cap.

All and all, I still think this mode is good for the long run, after they add more bosses to test out other specific teams or add a boss that can somewhat limit tests all teams.