The correspondence of U+A71D ⟨ꜝ⟩ towards the IPA click on letter ⟨ǃ⟩ is Hence accidental. Coincidentally, U+A71E ⟨ꜞ⟩ serves since the superscript variant in the extIPA percussive consonant ⟨¡⟩; the other percussive letters, ⟨ʬ⟩ and ⟨ʭ⟩, do not have superscript help in Unicode. ^You could obtain the file to look at it