Some comments from @sipa in #12702.

___

Yes, I think `importmulti` is superior in every way, except:
* Slightly less convenient to use (it requires redundant information, as you have to explicitly state what you want to import, and then give the keys/... to enable that).
* ~Doesn't support P2SH-P2WPKH yet~. Added in #14454

The latter can be fixed by just adding support for that case. The former can be improved by adding 'default' cases (e.g. if you prove a WIF private key, it can permit omitting the address, ...).

std::shuffle(vecSend.begin(), vecSend.end(), FastRandomContext());
    
    CReserveKey keyChange(pwallet);
    CAmount nFeeRequired = 0;
    int nChangePosRet = -1;
    std::string strFailReason;
    CTransactionRef tx;
    bool fCreated = pwallet->CreateTransaction(vecSend, tx, keyChange, nFeeRequired, nChangePosRet, strFailReason, coin_control);
    if (!fCreated)
        throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, strFailReason);
    CValidationState state;
    if (!pwallet->CommitTransaction(tx, std::move(mapValue), {} , keyChange, g_connman.get(), state)) {
        strFailReason = strprintf("Transaction commit failed:: %s", FormatStateMessage(state));
        throw JSONRPCError(RPC_WALLET_ERROR, strFailReason);
    }
    return tx->GetHash().GetHex();
}
static UniValue addmultisigaddress(const JSONRPCRequest& request)
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() < 2 || request.params.size() > 4) {
        std::string msg = "addmultisigaddress nrequired [\"key\",...] ( \"label\" \"address_type\" )\n"
            "\nAdd a nrequired-to-sign multisignature address to the wallet. Requires a new wallet backup.\n"
            "Each key is a Bitcoin address or hex-encoded public key.\n"
            "This functionality is only intended for use with non-watchonly addresses.\n"
            "See `importaddress` for watchonly p2sh address support.\n"