ROCK 5C requires 3A if not using NVMe HAT. The FPC connector and M.2 connector costs almost the same, but the Pi PCIe HAT ecosystem is good, that’s why we want to use it.
@dominik I believe you will want 5B+ instead of 5C. 5C / 5C Lite is mostly for project users. For home/desktop usage, we have 5B+ and 5 ITX. If you think those cost are high, we will consider introduce 5D, 5C in 5B form factor with similar price range as 5C.