Can we checkout page to another user via CSOM? Or, first checkout the page and then change to whom it is checked out to?
CheckoutUser fields are declared as
ReadOnly (Field.ReadOnlyField property is set to
True), it values could not be updated via CSOM.
From the other hand SP.File.checkOut() Method does not accept parameter for specifying the checkout user.
Therefore it does not seem possible to checkout file to another user.