A relevant discussion of this question with some interesting examples can be found in Calboli, Gualtiero (2009: 145-146). "Latin Syntax and Greek". In Philip Baldi & Pierluigi Cuzzolin (eds.). New Perspectives on Historical Latin Syntax vol. 1,pp. 65–193. Berlin-New York: De Gruyter. Here is the relevant quote (bold mine: Mitomino):
"TP Sulp. 51 Tab. II3 (graphio, script. interior) (...): que ominia / possita habeo penes me in horreis Bassianis / puplicis Putolanorum que ob omini / ui periculo meo est [[dico]] fateor. / Actum Putolis.
'all these wares I have in my possession in public Bassian stores of Pozzuoli. These wares are free from every danger as I myself confirm on my own responsibility. Done in Pozzuoli'
TP Sulp. 52 Tab. II3 (graphio, script. interior) (...): que ominia ab omini // ui priculo meo est fator. (S) Actum Putolis
In Calboli (1999: 342), I explained the syntagm omina [sic] ... est as a Graecism resulting from the continuous commercial contact of Eunus with Greek traders. Perhaps C. Eunus was ignorant of Latin grammar but knew the prestigious position of Greek, imitated by Latin authors and poets, and had no reason to avoid a construction his Greek customers used. Petronius 71,10: faciatur, si tibi uidetur, et triclinia provides a parallel from a commercial environment. This example is rejected by Hofmann & Szantyr: (1972: 431), but they give others from Late Latin authors, such as Comm. instr: 1,34,18: aurea...ueniet tibi saecla 'the golden age will come to you', 2,1,15: ut mysteria...omnia...compleatur 'to accomplish all the mysteries', and Chiron. 399: ea uitia difficiliter uincitur 'these faults it is difficult to correct'. More examples are given by Baehrens(1912: 483-496), who tried to demonstrate that this construction was native to Latin, because Latin had the same possibility of combining a neuter plural with a singular verb as Greek. A possible epigraphic example appears in the Année Épigraphique (1987/974 [Aegyptus 161]: principia a nouo aed[ifi]catum est (see Galdi 2004: 139)".
Concerning the first example above, it should be pointed out that an alternative proposal has been given in the specialized literature: cf. Adams (2016): "Another possibility is that est represents a constructio ad sensum, with the collectivity that precedes inspiring a singular verb. The neuter plural omnia, which occurs in the preceding clause with quae, is sometimes treated as a collective singular, and not only in late Latin".
Furthermore, in her study on Latin teaching materials in Antiquity Dickey (2010: 193) also provides an attested example on the influence of the rule of Greek at issue here on Latin. NB: Dickey's article is downloadable (bold mine: Mitomino)
"The person who provided this inflectional information, moreover, was not fully competent in Latin. In line 9 he uses a singular verb with a neuter plural subject: horum duorum cetera ut Cato declinatur. In Latin of all periods plural subjects require plural verbs, regardless of their gender, but in classical Greek a neuter plural [subject] does indeed take a singular [verb] (...) The provider of this inflectional information must therefore have himself been a well-educated Greek speaker whose Latin studies had not yet progressed to a very high level: he knew the rule that in formal written language a neuter plural subject takes a singular verb, but he did not grasp that that refinement did not apply to Latin".
Admittedly, it is a bit funny to compare the perspective of "a well-educated Greek speaker whose Latin studies had not yet progressed to a very high level" with the one given in the question above on "educated Romans who liked to imitate Greek writing". However, it could well be the case that, after all, the one who used, let's say, omnia fluit instead of cuncta fluunt could be considered by "educated Romans" as one who did not have a very high level of Latin...
Putting cases due to influence from Greek aside, I'd say that possible counterexamples to the rule that Latin neuter plural nouns do not trigger singular verb agreement can be explained away for different reasons: for example, attraction with another nearer NP, as in the following example from Sallust, commented on in this link.
sed ei cariora semper omnia quam decus atque pudicitia fuit (Sall. Cat. 25,3).
Finally, apropos of this question, let me tell you an anecdote. After reading the following assertion found in this work ("Another Greek peculiarity, 'neuter plural nouns take a singular verb', is not entirely without a parallel in Latin (Livy IX, 6): Paludamentaque detracta miserationem fecit"), I said to myself: Eureka! Not only I found a relevant example for the question above, but I also discovered a great example for a previous question of mine (see this link). That's really killing two birds with one stone, I thought. But my happiness only lasted a couple of minutes. I checked Livy's text and, alas!, I realized that the author of the abovementioned statement quite probably misanalyzed the sentence (NB: in any case Livy's text is interesting: e.g., see the non-trivial addition of id in some editions). As we say in Spanish, "¡mi gozo en un pozo!" (lit. 'my joy in a well!') or, should I say, "¡ nuestro gozo en un pozo!", since this is not an example of what you're looking for either.
