Let me rephrase my question. I am aware of that ultimately the current delivered depends on the PDP
of the power source. I am concerned that if I request 5A and the PDP can only deliver 3A, that no contract
will be negotiated and that the CYPD3177 will default to 5V_SAFE_PWR_EN. Is that the correct behavior?
You can check the Capability Mismatch part in PD Spec:
In this case the Sink Shall make a Valid request from the offered capabilities and Shall set the Capability Mismatch bit
What happens next depends on the policy of the power adapter you use.