A field sobriety test is not a search. Even if it was, this was shown to be by consent. City of Leawood v. Puccinelli, 2018 Kan. App. LEXIS 35 (June 22, 2018).
This heading in the too long opinion explains it all: “Mann was adequately apprised of the nature of the special search condition governing his parole, and specifically was cognizant of the diminished expectation of privacy he enjoyed as a condition of his parole when officers conducted the parole home compliance check at issue here.” United States v. Mann, 2018 U.S. Dist. LEXIS 102449 (E.D. Mich. June 20, 2018).*