The snipped use to generate the PR https://github.com/paritytech/polkadot/pull/4656

nicks-fix.ts

import { ApiPromise, WsProvider } from "@polkadot/api";
import axios from "axios";
import { writeFileSync } from "fs";
import { strict as assert } from 'assert'

async function findLastNicksBlock(block: number, key: string) {
	while (true) {
		let next = block + 1;
		const data = await axios.post(`https://kusama.api.subscan.io/api/scan/block`, {
			"block_num": next
		}, { headers: { "X-API-Key": key } })
		console.log(data.data)
		// @ts-ignore
		const spec = Number(data.data.data.spec_version);
		console.log(next, spec);

		if (spec != 1033) {
			break;
		}
		block = next;
	}

	console.log(block)
}

async function leftoverNicks(api: ApiPromise) {
	const key = process.env['API'] || "DEFAULT_KEY";

	function bin2string(array: Uint8Array){
		var result = "";
		for(var i = 0; i < array.length; ++i){
			result += (String.fromCharCode(array[i]));
		}
		return result;
	}

	// this should technically be the last block at which nicks pallet was IN the runtime.
	let block = 569325;
	const hash = await api.rpc.chain.getBlockHash(block);
	const atApi = await api.at(hash);
	const prefix = atApi.query.nicks.nameOf.keyPrefix();
	const pairs = await api.rpc.state.getPairs(prefix, hash);

	const allAccounts = (await api.query.system.account.entries()).map(([key, _]) => key.args[0]);
	console.log(`fetched ${allAccounts.length} accounts at ${hash}`)
	const globalTable = {};
	// @ts-ignore
	allAccounts.forEach((acc) => globalTable[api.registry.hash(acc.toU8a())] = acc.toHuman())

	const refunds = [];
	for (const [k, v] of pairs) {
		const [nick, deposit] = api.createType('(Vec<U8>, Balance)', v);
		const hashedKey = `0x${k.toHex().slice(-64)}`;
		// @ts-ignore
		const whoRaw = globalTable[hashedKey];
		const who = api.createType('AccountId', whoRaw);
		let currentReserved = (await api.query.system.account(who)).data.reserved;
		console.log(`${who.toHuman()} with old nick ${bin2string(nick.toU8a())} had deposit ${deposit.toHuman()}, current reserved balance ${api.createType('Balance', currentReserved).toHuman()}`);
		if (currentReserved.lt(deposit)) {
			console.log(`\t⚠️ does not have enough reserved balance for the refund`);
		}
		refunds.push({who, deposit })
	}

	writeFileSync("refunds.json", JSON.stringify(refunds));
	for (let { who, deposit } of refunds) {
		console.log(`(${api.createType('AccountId', who).toU8a()}, ${deposit})`);
	}
}

async function main() {
	const provider = new WsProvider("ws://127.0.0.1:9924");
	const api = await ApiPromise.create({ provider });
	console.log(`Connected to node ${(await api.rpc.system.chain()).toHuman()} [ss58: ${api.registry.chainSS58}]`)
	await leftoverNicks(api)
}

main().catch(console.error).finally(() => process.exit());