We are having a dispute here whether we must drive the nCONFIG pin with a open drain gate (together with a pull-up to VCCIO) or if we can use a push-pull driver (without any pull). Some of us thinks the documentation in some places can be interpreted as if the nCONFIG pin also can be an output while I personally beleive it will always be an input, during both configuration and in user mode.
Yes, nCONFIG pin is input only during user mode.
Upon power-up, the nCONFIG pin must be pulled high. Connect this pin directly or through a 10-kΩ resistor to VCCIO.
check section 2.3.2 from below link also refer pin connection guidelines.