Technically, no, but there are may in the Western Church who would like to make it a dogma that Mary is the Co-Redemptrix, and no one else. Certainly the Western Church is not opposed to Catholics holding such beliefs.
Some modern Orthodox Christians don't like the words "Most Holy Theotokos, Save Us."
It's not a matter of "liking" or "disliking," but a matter of theological concern that a human being is being elevated to a demi-god.
"Once people have been fully converted to Christ, the love of the Panagia follows naturally."
Goes without saying.
The "no one else" part I dispute. Here we have a proponent of such dogma and he clearly writes that the co-redemptive status of Mary is an icon of the co-redemptive Church and so all of us. See the passage I highlighted a few posts ago. Now, you would not dispute that there are things about Mary that are unique, but the proposed dogma is designed to underscore rather than deny our own participation in the redemptive work of Christ.
a matter of theological concern that a human being is being elevated to a demi-god
My point with "Theotokos save us" is not that there is no concern like that, but that the Orthodox Church has this devotion, and I am sure millions of the Orthodox repeat the prayer understanding it correctly, not as demi-godship of Mary but as her unique participation in the economy of salvation. But that Orthodox prayer is diagrammatically not that Mary is a co-Redemptrix, but the she is, gasp, Redemptrix. Just like I do not make it my business to presume that the Orthodox praying that are idolaters, please do not make it your business to presume that the Catohlics, who pray less strident a prayer with the "co-" attached, are.