PTR08060W inhibit must controlled only by an open drain device with no pullup resistor or voltage.
The normal soft start function when power is applied or the inhibit pin open duration to 3.3V is about 4msec. Adding any capacitor to the inhibit pin will only delay power on function .The additional component to ground will not change the normally soft power-up dv/dt. It will still be about 4mS as listed in the specification under on-off inhibit or normal power up.
Tom