Isaiah 52:15, what does the Suffering Servant do to the nations?

JPS and NRSVUE give the sense of “startle” but note that the meaning is uncertain. This reading mainly depends on Arabic nāza “to leap” with the hifil having the meaning “cause to leap up” (which is not quite the same thing as startling, with the Arabic word lacking the emotional import of “startle”), with the support of the LXX θαυμάσονται referring to the astonishment of the nations but this may be an elucidation from the context (v. 14). All the other witnesses to the text (other than Symmachus’ ἀποβάλλει which misreads the verb as זנח “reject”) understand the verb as “sprinkle”, e.g. ῥαντίσει “he will sprinkle, spatter” in Theodotion and Aquila, יְבַדַר “he will scatter, sprinkle” in the Aramaic targum, ܡܕܟܐ “he will purify” in the Peshitta, and asperget “he will spatter, sprinkle” in the Vulgate. HALOT 683 gives only “sprinkle, spatter something” for נזה, with a cognate in Akkadian nezû “to spatter, urinate, defecate”. The main problem with understanding the verb as “sprinkle” is the unusual grammar, with the sentence omitting the liquid or substance that is sprinkled and the preposition על is absent with the direct object גוים רבים to indicate on what the liquid is being sprinkled.
The preposition occurs most of the time but not always; in Leviticus 4:6, 17 the accusative marker occurs instead which would not occur in poetry as is found in the Suffering Servant song. And in Exodus 29:21, Leviticus 14:7, Numbers 19:19 the liquid that is being sprinkled is omitted and has to be inferred from the context. Another uncertainty in the text is משחת in the preceding verse, which is a hapax legomenon usually understood as “marred” or “disfigured”, which prompts the startling in the non-sprinkling reading. But the Great Isaiah scroll at Qumran (1QIsaª) instead has משחתי, and so derives the verb from משח “anoint” rather than שחת “ruin”. This fits the context with the initial verse: “See, my servant succeeds, he rises up, he is exalted and very high. Just as there were many astonished at you (עליך), so you anointed (משחת) his visage beyond that of men. His form is beyond that of sons of men, so he shall sprinkle many nations; kings shut their mouths because of him” (v. 13-15). The shift from the first to second person is a difficulty in the text which 1QIsaª attempted to smooth by using the first person (משחתי), but which explains for the form of the verb in the MT. And this fits well with the sacerdotal reading since in Leviticus 16, the high priest who sprinkles on Yom Kippur for atonement (v. 14-15) must first be anointed (v. 32).
This comports well with the sacerdotal theme throughout the poem. KyeSang Ha in Cultic Allusions In The Suffering Servant Poem (Isaiah 52:13-53:12) (Andrews, 2009), found that “[a]lthough the sanctuary itself is not explicitly mentioned in the Poem, the Servant of Yahweh is portrayed as a cultic sacrificial animal (שֶׂה), a cultic expiatory offering (אָשָׁם), and a cultic priest performing significant cultic activities (יפַגְּיִעַ ,יצַדְִּיק ,יַזּהֶ), to all of which the sin-bearing clauses (נשָָׂא חטֵאְ/סָבַל עָוֹן) are closely related”, concluding that “the Hebrew sacrificial cult is the background of the Suffering Servant Poem” (pp. i-iii). My own suspicion is that the occasion of this poem was the completion of the Second Temple in 515 BCE and the restoration of animal sacrifice, which led the author to make an analogy between cultic expiation and the experience of the Babylonian golah. This is based somewhat on the redactional theory of Rainer Albertz (Israel in Exile; SBL, 2003) who finds that the first edition of Deutero-Isaiah (which incorporated an older collection of Cyrus oracles) was completed in c. 521 BCE at the accession of Darius the Great, with the original ending at 52:7-12, with a call to arms for the group associated with Zerubbabel to leave Babylonia without delay (as in 48:10), with Babylon facing potential disaster (47:11). The second edition was produced c. 500 BCE (which was presupposed by Trito-Isaiah, ch. 56-66), which added ch. 54-55, collectivized the Servant as “servants”, and edited ch. 40-52 to focus on Zion. This would make the Suffering Servant song an appendix to the first edition, added sometime around or after 515 BCE.
If the poem was occasioned by the reinstitution of worship at the Temple, then the individualistic features of Servant may reflect on the exilic experience of the priesthood. According to Jeremiah 52:24-27, the last high priest Seraiah and his assistant were deported in 587 BCE and brought before Nebuchadnezzar and then summarily executed. His son Jozedek lived in exile and never performed cultic duties as high priest. The high priest of the restored Temple was Seraiah’s grandson Joshua (1 Chronicles 6:14-15), who Zechariah depicted in 3:6-9 as a mediator in cleansing Israel of its iniquities (עון, cf. Isaiah 53:5-6, 11) on Yom Kippur, who himself was restored from a state of filth in his investiture as high priest (v. 4). Interestingly, though the Servant song mixes various cultic metaphors together, it refers to the Servant bearing the sins of many (חטא רבים נשא) in 53:11 which recalls both the role of priests in bearing (נשא) the guilt of the people (Exodus 28:38, Leviticus 10:17) and the scapegoat sent into the wilderness on Yom Kippur that bears all the sins of the people (Leviticus 16:22). Is there a parallel here between the scapegoat and the collective Servant of Yahweh sent into the golah bearing the sins of all? The Servant was commissioned not only to restore the tribes of Israel but to bring light to the nations to bring salvation to the ends of the earth (42:1-4, 49:1-6), even though Israel was despised and abhorred by the nations (49:7). So the golah community not only removes the guilt from Israel but also expiates the nations for what they did and brings them to Yahweh. Isaiah 52:15 in the MT says the Servant would sprinkle many nations (יזה, cf. Leviticus 4:6, 17, 5:9, 6:27, 8:17, 30; רבים, cf. Isaiah 53:11), which is suggestive of the Servant carrying out a priestly ministry of purifying the uncleanness of all nations.