Complacencies of the peignoir; and late... {Coffee and oranges in a sunny chair}

That line, the first of Wallace Stevens' "Sunday Morning," has five unstressed syllables in a row.
(I define a stressed syllable here as the main stress of a content word.)

There is a secondary stress on the fourth syllable of "complacencies." That leaves only
three unstressed syllables: "of the peign-" "of" is more marked than "the,"
but the truth is that it doesn't really matter too much. The line could be read aloud in
more than one acceptable way.

Unstressed syllables can occupy strong metrical positions unproblematically.
A lexical stress in a weak metrical position, in contrast, is much more unusual:

"If deSIGN govern in a thing so small." [Frost, "Design"]

Yet with monosyllabic words, the effect is fairly commonplace:

"Of a green thought in a green shade" [Marvell]

Word-boundary, then, is a factor, as Paul Kiparsky was the first to demonstrate.

At the beginning of a line, or after a pause, there is no problem with a lexical stress in weak position:

"Gently to hear, kindly to judge, our play." [Prologue, Henry V]