Some commentators hold that since kudos is a singular word it cannot be used as a plural and that the word kudo is impossible. But kudo does exist; it is simply one of the most recent words created by back-formation from another word misunderstood as a plural. Kudos was introduced into English in the 19th century; it was used in contexts where a reader unfamiliar with Greek could not be sure whether it was singular or plural. By the 1920s it began to appear as a plural, and about 25 years later kudo began to appear. It may have begun as a misunderstanding, but then so did cherry and pea."
To your reservations: you're not alone. I read the comments with the NY Times review, and several were not only unimpressed with the staging, but said it exposed weaknesses in the show itself. I was genuinely startled, but realized: as always, every audience member sees an entirely different production. I hear a fair amount of this about "Hamilton" these days, especially from those who'e waited a year to get in and followed Brantley's advice about a 2nd mortgage. But I remember it about "Chorus Line" and "Rent," too. "Sunday" has always been a show that invites the audience to lean in, listen, to "come to it" rather than the opposite. For me, this production's strength is its steadfast refusal to oversell any component, to woo its audience (Chromolume aside). But even on the way out I heard people grousing about how cheap it looked.