Is the source of shuhari Zeami's Fushikaden?

The reference report says the supposed source of shuhari in Zeami could not be confirmed. It checked Zeami-related indexes, dictionaries of Japanese language, tea ceremony sources, and martial-arts reference works, and found that one work links the term to Fūshikaden, but the word shuhari itself does not appear there.

Reading notes

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• The investigation began with Zeami-related sources, including an index of terms in his transmitted writings, but found no matching entry for shuhari.
• A Japanese dictionary states that the term expresses stages of training in tea ceremony and martial arts, so the search was widened.
• In the entry for shuhari in Nihon kokugo daijiten 6, a quotation from Chawa-shō defines shu, ha, and ri in relation to tea ceremony.
• Chawa-shō is identified as a tea treatise by Yokoi Tansho, supplemented and revised by Kawakami Fuhaku and Hayama Sōiku.
• Kendō jiten says the term came to be used for stages of training from its use in Fuhaku hikki by Kawakami Fuhaku in 1749.
• Budō densho o yomu relates shu, ha, ri to Fūshikaden, but the word shuhari itself does not appear there.
• The report closes by listing other materials already checked, including works on tea ceremony and budō.