I've just found this comment in Damascius' lectures on Plato's Philebus §171. Damascius is listing the various possible forms of false pleasures. After those experienced by people in dreams or by the insane he gives this example:
ἀπὸ τῶν ἐν ἐλπίσι κεναῖς· ὃ καὶ οἱ πεπαιδευμένοι πάσχουσιν ἀρίστας πολιτείας ὑπογράφοντες καὶ ταύταις μὴ παρούσαις ἐφηδόμενοι.
Next: those that come from empty hopes. This is what educated types experience when they sketch out ideal constitutions and take pleasure in them although they are not real.
Westerink's note assures the reader that Damascius certainly cannot have been making a sarcastic remark about Plato himself, who may, we can suppose, have taken a certain amount of pleasure in thinking about ideal yet unrealised constitutions. Instead, Westerink sees a reference to some otherwise unknown contemporaries of Damascius. I don't know enough about Damascius to judge his sense of humour (I suspect he may not have had one) but I like the comment all the same.