the observation that the neutralizing environment is unstressed, but the nuclei are different in stressed syllables. That fits with vowel contrasts often being preserved differently in stressed and unstressed environments and that the usual relationship is that there are more contrasts in stressed syllables than in unstressed ones since previously-distinctive vowels fell together in unstressed environments.

The idea that original might fall together with original is unproblematic and so internally, a complex nucleus *ue can be reconstructed