A pattern of reference to Apollo in Attic Tragedy?

Sophocles Electra 1376 -1383
{ΗΛ.} Ἄναξ Ἄπολλον, ἵλεως αὐτοῖν κλύε,
ἐμοῦ τε πρὸς τούτοισιν, ἥ σε πολλὰ δὴ
ἀφ' ὧν ἔχοιμι λιπαρεῖ προὔστην χερί.
Νῦν δ', ὦ Λύκει' Ἄπολλον, ἐξ οἵων ἔχω
αἰτῶ, προπίτνω, λίσσομαι, γενοῦ πρόφρων
ἡμῖν ἀρωγὸς τῶνδε τῶν βουλευμάτων,
καὶ δεῖξον ἀνθρώποισι τἀπιτίμια
τῆς δυσσεβείας οἷα δωροῦνται θεοί.

Wherein Electra submits a request to Apollo. First question, why is there a comma after Ἄπολλον and why do the translators (Jebb, Grene, Carson, Pound-Fleming) read ἵλεως as an adverb with κλύε rather than an adjective with Ἄπολλον? Concerning word order, the anarthrous adjective following the head noun is unremarkable. On the other hand, an adverb in clause initial position is equally unremarkable. While LSJ cites ἵλεως as an adjective used in reference to gods, I wonder if we find in Attic Tragedy a pattern of reference to Apollo which determines the reading of this line. I did a little work on this.

Here is an example of ἵλεως with the same verb κλύω in a request addressed to Apollo.

Sophocles Electra 665-668
Ταῦτ', ὦ Λύκει' Ἄπολλον, ἵλεως κλύων
δὸς πᾶσιν ἡμῖν ὥσπερ ἐξαιτούμεθα·
τὰ δ' ἄλλα πάντα καὶ σιωπώσης ἐμοῦ
ἐπαξιῶ σε δαίμον' ὄντ' ἐξειδέναι·
τοὺς ἐκ Διὸς γὰρ εἰκός ἐστι πάνθ' ὁρᾶν.

Here is an example of ἵλαος used in a request addressed to Φοῖβε Apollo.

Theognis Eleg., Elegiae (0002: 001)
“Theognis, 2nd edn.”, Ed. Young, D. (post E. Diehl)
Leipzig: Teubner, 1971.
Book 1, line 782

ἦρος ἐπερχομένου κλειτὰς πέμπωσ' ἑκατόμβας
τερπόμενοι κιθάρηι καὶ ἐρατῆι θαλίηι
παιάνων τε χοροῖσ' ἰαχῆισί τε σὸν περὶ βωμόν·
ἦ γὰρ ἔγωγε δέδοικ' ἀφραδίην ἐσορῶν
καὶ στάσιν Ἑλλήνων λαοφθόρον. ἀλλὰ σύ, Φοῖβε,
ἵλαος ἡμετέρην τήνδε φύλασσε πόλιν.

Here is an example from Soph. Electra where Φοῖβε is followed by an adjective προστατήριε but I could not find a pattern where Ἄναξ Ἄπολλον was followed by an adjective.

Sophocles, Electra 634-642

{ΚΛ.} Ἔπαιρε δὴ σὺ θύμαθ' ἡ παροῦσά μοι
πάγκαρπ', ἄνακτι τῷδ' ὅπως λυτηρίους
εὐχὰς ἀνάσχω δειμάτων ἃ νῦν ἔχω.
Κλύοις ἂν ἤδη Φοῖβε προστατήριε,
κεκρυμμένην μου βάξιν· οὐ γὰρ ἐν φίλοις
ὁ μῦθος, οὐδὲ πᾶν ἀναπτύξαι πρέπει
πρὸς φῶς, παρούσης τῆσδε πλησίας ἐμοί,
μὴ σὺν φθόνῳ τε καὶ πολυγλώσσῳ βοῇ
σπείρῃ ματαίαν βάξιν εἰς πᾶσαν πόλιν·

In Aeschylus. we find numerous examples of ἄναξ Ἄπολλον, here is one which is followed by the familiar request to be given a hearing, although the wording is different.

Aeschylus Eumenides 198
{Χο.} ἄναξ Ἄπολλον, ἀντάκουσον ἐν μέρει.

This is a work in progress. But I will go ahead an post this since I might otherwise just forget about it and move on to something else.