Please tell me about the operation of HMC574A.

Hi, I would like to use HMC574A.

So, I have a question. Please help me.

Question:

I am experimenting with an evaluation board.

The A and B terminals of the HMC 574A, 
I think that the logic level needs to be different at every timing.
First of all is this idea correct?

Take the evaluation board as an example.
If you connect the A / B terminal before and after the inverter pass by 74 IC,

I think that there is a moment when the A / B terminal becomes the same logic level in nanosecond order.

①What is the state of the RF switch when the A / B terminals are at the same logic level?

②Are there any restrictions on using time when the A and B terminals are at the same logic level?

Best Regards,

Naohisa