I don't recognize the pad shape for the component next to the input connector on the FILTER board. Is this used for something? I've been shorting across it.
It is a 3-TERMINAL FEEDTHROUGH FILTER, you can review details in the documentation,
Here is the User guide (see page 3) link: https://www.analog.com/media/en/technical-documentation/user-guides/scp-filter-evalz.pdf or navigate from the product page https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/scp-filter-evalz.html.