I'm not sure anyone's done this yet, but I thought it might be instructive to see where the word empty "kenōs" is used in other places.
Saint-Andre translation of PD29 which includes the scholia commentary
29 Among desires, some are natural and necessary, some are natural and unnecessary, and some are unnatural and unnecessary (arising instead from groundless opinion).
(Epicurus regards as natural and necessary desires which bring relief from pain, as e.g. drink when we are thirsty ; while by natural and not necessary he means those which merely diversify the pleasure without removing the pain, as e.g. costly viands ; by the neither natural nor necessary he means desires for crowns and the erection of statues in one's honour.--Scholia)
PD30 also addresses empty beliefs/opinions/doctrines κενὴν δόξαν "kenēn doxan":
Hicks translation
30 Some natural desires, again, entail no pain when not gratified, though the objects are vehemently pursued. These desires also are due to groundless opinion, and when they are not got rid of, it is not because of their own nature, but because of the man’s groundless opinion.
Saint-Andre translation
30 Among natural desires, those that do not bring pain when unfulfilled and that require intense exertion arise from groundless opinion; and such desires fail to be stamped out not by nature but because of the groundless opinions of humankind.
Epicurus wiki translation:
Those natural desires which create no pain when unfulfilled, though pursued with an intense effort, are also due to groundless opinion; and if they are not dispelled, it is not because of their own nature, but because of human vanity.
Nussbaum translation, p.153
Whenever, among those natural desires that do not lead to pain if they are not fulfilled, an intense eagerness (spoudē suntonos) is present, they too are the products of false belief. And it is not on account of their own nature that they are not dispelled, but in account of the human being's empty believing. (On suntonos "intense", see Nussbaum, chapter 8). Philodemus uses the word of the sort of anger the Epicurean will avoid.
PD37 uses empty in a novel way, to describe "empty sounds, words, prattle" The phase is φωναῖς κεναῖς "phōnais kenais" and yes that's where English "phone" comes from, so φωναῖς κεναῖς = empty sound, meaningless yelling, blah blah blah
Saint-Andre translation
37 Among things that are thought to be just, that which has been witnessed to bring mutual advantage among companions has the nature of justice, whether or not it is the same for everyone. But if someone legislates something whose results are not in accord with what brings mutual advantage among companions, then it does not have the nature of justice. And if what brings advantage according to justice changes, but for some time fits our basic grasp of justice, then for that time it is just, at least to the person who is not confused by empty prattle but instead looks to the facts.
The word empty is also used here for the ἀρετὰς κενὰς καὶ ματαίας "empty and trifling virtues (aretas)"
116. I summon you to sustained enjoyment and not to empty and trifling virtues, which destroy your confidence in the fruits of what you have. ἐγὼ δʼ ἐφʼ ἡδονὰς συνεχεῖς παρακαλῶ καὶ οὐκ ἐπʼ ἀρετὰς κενὰς καὶ ματαίας καὶ ταραχώδεις ἐχούσας τῶν καρπῶν ἐλπίδας.
And in Fragment 202, we get "empty beliefs/groundless opinions" κεναῖς δόξαις (kenais doxais) in juxtaposition with "following nature" so, in a way, setting up the dichotomy of natural vs empty.
Fragment 202. He who follows nature and not groundless opinions is completely self-reliant. With regard to what is enough by nature, everything he owns is a source of wealth; whereas with regard to unlimited desires, even the greatest wealth is poverty.
ὁ οὖν τῇ φύσει παρακολουθῶν καὶ μὴ ταῖς κεναῖς δόξαις ἐν πᾶσιν αὐτάρκης· πρὸς γὰρ τὸ τῇ φύσει ἀρκοῦν πᾶσα κτῆσίς ἐστι πλοῦτος, πρὸς δὲ τὰς ἀορίστους ὀρέξεις καὶ ὁ μέγιστος πλοῦτός ἐστι πενία.
Same with 422 κενὰς δόξας "groundless opinions"
422. We need pleasure when in pain because of its absence; but when we are not experiencing such pain, and are perceiving stably, then there is no need for pleasure. For it is not the needs of nature which, from outside us, create harm, but desire driven by groundless opinions.
τότε χρείαν ἔχομεν τῆς ἡδονῆς, ὅταν ἐκ τοῦ μὴ παρεῖναι αὐτὴν ἀλγῶμεν· ὅταν δὲ τοῦτο μὴ πάσχωμεν ἐν αἰσθήσει καθεστῶτες, τότε οὐδεμία χρεία τῆς ἡδονῆς· οὐ γὰρ ἡ τῆς φύσεως ἔνδεια τὴν ἀδικίαν ποιεῖ ἔξωθεν, ἀλλʼ ἡ περὶ τὰς κενὰς δόξας ὄρεξις.
471. (Saint-Andre) It is rare to find a man who is poor with regard to the aims of nature and rich in groundless desires. For a fool is never satisfied with what he has, but instead is distressed about what he doesn't have. Just as those who are feverish through the evil of their sickness are always thirsty and desiring the opposite of what they should, so those whose souls are in a bad condition are always poor in everything and through their greed fall into ever-changing desires. [note] σπάνιόν γε εὑρεῖν ἄνθρωπον <πένητα> πρὸς τὸ τῆς φύσεως τέλος καὶ πλούσιον πρὸς τὰς κενὰς δόξας. οὐδεὶς γὰρ τῶν ἀφρόνων οἷς ἔχει ἀρκεῖται, μᾶλλον δὲ οἷς οὐκ ἔχει ὀδυνᾶται. ὥσπερ οὖν οἱ πυρέττοντες διὰ κακοήθειαν τῆς νόσου ἀεὶ διψῶσι καὶ τῶν ἐναντιωτάτων ἐπιθυμοῦσιν, οὕτω καὶ οἱ τὴν ψυχὴν κακῶς ἔχοντες διακειμένην πένονται πάντων ἀεὶ καὶ εἰς πολυτρόπους ἐπιθυμίας ὑπὸ λαιμαργίας ἐμπίπτουσιν.
[NOTE 471] In the second chapter of the Nicomachean Ethics, Aristotle characterizes desires as groundless and trifling (κενὴν καὶ ματαίαν) if they are not related to or subsumed under an overarching goal of life; in this fragment and in Fragment 442, Epicurus applies the same terms to certain kinds of desires. (See also 116 above)
Fr. 485. Unhappiness (kakodaimon) is caused by fears or by endless and empty desires; but one who is able to rein these in creates for oneself a blissful understanding (logismon).
ἢ γὰρ διὰ φόβον τις κακοδαιμονεῖ ἢ διʼ ἀόριστον καὶ κενὴν ἐπιθυμίαν· ἅ τις χαλινῶν δύναται τὸν μακάριον ἑαυτῷ περιποιῆσαι λογισμόν.
χαλινῶν genitive: rein, bit, something that restrains
μακάριον makarion = blissful, the same word used to describe the gods
περιποιῆσαι keep, preserve; procure, secure, achieve.
512. "I spit on the kalon and on those who wonder at it in an empty fashion -- whenever it does not produce any pleasure."
προπτύω τῷ καλῷ καὶ τοῖς κενῶς αὐτὸ θαυμάζουσιν, ὅταν μηδεμίαν ἡδονὴν σοιῇ.
That's a translation of Nussbaum's and it's much more literal (and better) than other paraphrases I've read of this Fragment. Here we see κενῶς "kenōs" empty used to describe how some people wonder at The Noble/The Beautiful τῷ καλῷ Tō Kalō(n)