Slack deep link into client: how to link into im if im not open

Question

I made a platform-independent contactlist-style standalone client for Slack in Qt/C++.

It uses Slack's Deep Linking scheme to navigate through the official Slack-Client when clicking Items in my ContactList.

The problem is, when clicking a user item in my list (which gets the user id and creates the link), the slack client will only enter the im dialog, if it was open before (if i have a im history with that user).

Otherwise it will just show the team directory context for that user, where i manually have to click "message" to actually enter the chat dialog.

Is there really no way to do it right just with slack:// deep links?

The only solution that i can think of right now is to open a new im, if not exist, using api call from my application before opening the link. or maybe open im's for all users at app launch.

But that's kind of a dirty workaround, that i don't like.

Is there a more elegant way to go directly to a new IM than this?

EDIT: quick Workaround without error handling is working this way:

void Window::contactListDoubleClicked(QTableWidgetItem *item)
{
    QString id = listWidget->item(item->row(),1)->text();
    int type = listWidget->item(item->row(),3)->text().toInt();

    if (type == 1) { // if item is a user, we have to ensure that im exists by requesting im.open
        QEventLoop eventLoop;
        QNetworkAccessManager mgr;
        QObject::connect(&mgr, SIGNAL(finished(QNetworkReply*)), &eventLoop, SLOT(quit()));
        QNetworkRequest req(QUrl(QString("https://slack.com/api/im.open?token=").append(m_token).append("&user=").append(id)));
        QNetworkReply *reply = mgr.get(req);
        // block stack until reply is ready
        eventLoop.exec();
        qDebug() << reply->readAll();
        QDesktopServices::openUrl(QUrl(QString("slack://user?team=XXXXXXXX&id=").append(id),QUrl::TolerantMode));
    } else {
        QDesktopServices::openUrl(QUrl(QString("slack://channel?team=XXXXXXX&id=").append(id),QUrl::TolerantMode));
    }
}