Does Native Library Support Master Client and Host Migration?

The C++ API changed right?
SetMasterClient is still there:
https://doc.photonengine.com/en-us/realtime/current/gameplay/hostmigration but I don't see a clear way to call it or implement a method in a custom LoadBalancingClient (nor MutableRoom) to access this info without changing LoadBalancing, how can I do that?
I guess ,that to overload a custom type making a fake string that holds a nByte to change the room property with something like this is really crazy innit?.

//----
static TSharedPtr<nByte> tempData = MakeShared<nByte>(ExitGames::LoadBalancing::Internal::Properties::Room::MASTER_CLIENT_ID);
			const FNByteFakeString fakeNByteString(tempData.Get());
			ExitGames::Common::Hashtable hash;
			hash.put(fakeNByteString, static_cast<int>(PlayerNumber));
			//auto merged = ExitGames::LoadBalancing::Internal::Utils::stripKeysWithNullValues(hash);
			return Room.addCustomProperties(hash);
//---

//having
class FNByteFakeString : public ExitGames::Common::Object
	{
	public:
		nByte Data;
		FNByteFakeString(nByte* InData)
			: Object(InData, ExitGames::Common::TypeCode::STRING, ExitGames::Common::TypeCode::STRING, true)
			, Data(*InData)
		{
		}
		nByte& operator=(nByte aNum)
		{
			Data = aNum;
			return Data;
		}
		bool operator==(const nByte& Rhs) const
		{
		  return Data == Rhs;
		}

		virtual ExitGames::Common::JString typeToString() const override
		{
			return "STRING";
		}

		virtual ExitGames::Common::JString& toString(ExitGames::Common::JString& retStr, bool withTypes) const override
		{
			return retStr;
		}
	};

namespace ExitGames
{
	namespace Common
	{
		namespace Helpers
		{
			template<> struct ConfirmAllowedKey<FNByteFakeString>
			{
				typedef nByte type;
				static const nByte typeName = TypeCode::STRING;
			};
		}
	}
}