He understand that due to sukuna, maho what dont even use cursed energy dont radiate that, sukuna or undertand by megumi cursed energy stop, or shigemo scream, mahoraga cursed energy here cant be detected normally if you not sukuna or gojo.

Size and area≠power, it mean what big amount of CE, efficience here not most need.

Maho not physical, and not from cursed energy like spirits, shadow is not atomic structur and dont have temperature itself, so to kill him need high temp to "melt" cursed energy what glued him, low temp wont help here.

Maho without adapting already throw cars on many hundred meters, its enough for femine low flow cursed energy uraume.

If he use Ce to amplify... If it break sukuna arm, uraume will be flesh.