It would be cool if there was an option in Bitcoin Core for disabling the system tray entirely.

QValidator(parent)
{
}
QValidator::State ProxyAddressValidator::validate(QString &input, int &pos) const
{
    Q_UNUSED(pos);
    
    proxyType addrProxy = proxyType(CService(input.toStdString(), 9050), true);
    if (addrProxy.IsValid())
        return QValidator::Acceptable;
    return QValidator::Invalid;
}