Regarding the pronunciation of weak vowels in American English, do you think this theory provides a good explanation?

In unstressed syllables, /ɪ/ (kit) and /ɐ/ (cut) undergo reduction. The degree of reduction differs from person to person and from word to word.

- When /ɪ/ and /ɐ/ are fully reduced, both sound like a schwa, which is the most relaxed sound.

- When /ɪ/ and /ɐ/ are partially reduced to schwa, they are influenced by surrounding sounds, meaning no single phonetic symbol can precisely represent their pronunciations.