Portals to the Outlands, Arcadia or Acheron may be arches of red tape. They will twist the instructions of chaotic summoners. If the alignment is identical, the creature will do its best to serve well. Chaotics cannot divine. Illusions do not even manifest.
Wild magic fails.
Elemental magic requires a bit of the element native to the plane, and there is good earth and water only in Nemausus. Spell keys might be able to allow a chaotic to use divinations, but keys to overcome other limitations of the plane seem unlikely. Wizardly spell keys are one-twelfth of a cog, colored appropriately and marked with the sigil of a spell school. If twelve such keys, one for each school, are joined and absorbed by a wizard, they will never be lost, but all spells cast off the plane will be at half effect. Or, for necromancy, a bit of a modron's body and a prayer in Chinese.