How to read OC0A when in CTC (toggle) mode?
If you look into the Arduino Core, you'll find this code for the digital read:

int digitalRead(uint8_t pin)
{
    uint8_t timer = digitalPinToTimer(pin);
    uint8_t bit = digitalPinToBitMask(pin);
    uint8_t port = digitalPinToPort(pin);

    if (port == NOT_A_PIN) return LOW;

    // If the pin that support PWM output, we need to turn it off
    // before getting a digital reading.
    if (timer != NOT_ON_TIMER) turnOffPWM(timer);

    if (*portInputRegister(port) &amp; bit) return HIGH;
    return LOW;
}


That means, disabling PWM is just weird feature in digitalRead.

For reading bitRead(PORTB,3); I'm not so sure if you'll get output value of OC0A, it might be different signal line internally. However you'll get logical level on the port pin by reading bitRead(PINB,3);.