The BNC clock connectors on the input modules all output wordsync (either 44.1Khz or 48Khz). How they work is the DAC syncs to the incomming stream and determines if it is in the 44.1Khz family or in the 48Khz family then it outputs the corresponding wordsync. So your wordsync input needs to be able to handle changing wordsync and wordsync that is at the wrong rate. For example if you have a ProUSB input and a S/PDIF input and you are using the wordsync output on the S/PDIF input but you have the ProUSB currently selected then the wordsync output will follow the ProUSB not the S/PDIF input. When you switch to the S/PDIF input then the wordsync output will follow the S/PDIF input frequency.
All multiples of 44.1Khz (88.2Khz, 176.4Khz, etc… including DSD) will output a 44.1Khz wordsync.
All multiples of 48Khz (96Khz, 192Khz, etc…) will output a 48Khz wordsync.
If the source switches from the 44.1Khz to 48Khz family, the wordsync will take a portion of a second to follow that change, and will momentarily be at the wrong rate.
Whatever source is selected is the source that the wordsync will follow. If you always want the wordsync to follow one source, then that is the only source you can select.
Sources like MSB transports and the Aurenderer all detect whether the wordsync in is at the correct frequency before they use it internally, and they have a backup internal clock they use when worsync in is at the wrong rate or isn’t present.