addmultisigaddress creates an address respecting the setting, being unable to generate a specific type of address without also adding it to the wallet seems wrong.

I suppose in the future `addresstype` may be refactored to be wallet-specific, which would leave this non-wallet rpc call without an argument. Perhaps there should just be an optional parameter to set it.
UniValue operator()(const CNoDestination& dest) const { return UniValue(UniValue::VOBJ); }
    UniValue operator()(const CKeyID& keyID) const
    {
        UniValue obj(UniValue::VOBJ);
        CPubKey vchPubKey;
        if (pwallet && pwallet->GetPubKey(keyID, vchPubKey)) {
            obj.pushKV("pubkey", HexStr(vchPubKey));
            obj.pushKV("iscompressed", vchPubKey.IsCompressed());
        }
        return obj;
    }
    UniValue operator()(const CScriptID& scriptID) const
    {
        UniValue obj(UniValue::VOBJ);
        CScript subscript;
        if (pwallet && pwallet->GetCScript(scriptID, subscript)) {
            ProcessSubScript(subscript, obj, IsDeprecatedRPCEnabled("validateaddress"));
        }
        return obj;
    }
    UniValue operator()(const WitnessV0KeyHash& id) const
    {
        UniValue obj(UniValue::VOBJ);
        CPubKey pubkey;
        if (pwallet && pwallet->GetPubKey(CKeyID(id), pubkey)) {
            obj.pushKV("pubkey", HexStr(pubkey));
        }
        return obj;
    }
    UniValue operator()(const WitnessV0ScriptHash& id) const