The first board that uses the size is the MS-Terminator H770, an Intel-branded LGA 1700 board with an H770 chipset. The 245mm x 175mm board is almost exactly as long as a mini-ITX board, “long” in the sense of going down towards the PCIE area, (170mm) but 75mm wider. On top of the PCIE 5.0 slot, other highlights include Wi-F 6, Bluetooth 5.2, and four M.2 slots in total (they’re stacked), all sadly sticking with PCIE 4.0 speeds. The YTX format would acknowledge that you can’t do anything about that, while taking advantage of the space to add much-needed M.2 capacity. The YTX board won’t fit in a standard mini-ITX tray, but a micro-ATX case would hold it unmodified.