I wonder what signals they actually route out the FMC card. The website doesn't give a lot of information, but it seems like probably just ChipLink which they claim is their serialized TileLink bus protocol. So, you probably wouldn't be able to just plug a low-cost FMC module into the board. But with something like https://www.xilinx.com/products/boards-and-kits/ek-s6-sp605-... for another $500, you could theoretically use the DVI connector to provide a framebuffer, the PCI connector to interface to an NVME drive, and the FPGA to implement the logic of a TileLink endpoint as well as a minimal framebuffer and PCIe root complex.