Any N100 board that has a PCIe connector exposed is basically mini ITX sized, which kind of defeats the whole purpose of a SBC imo.

There are lots of problems with the Pi 5 (the absurd power draw, the lack of eMMC, breaking 10 years of GPIO compatibility), but the PCIe connector is definitely not one of them. In fact it's probably the best thing about it by far because it sets up a new standard, and soon every random SBC will have the same PCIe out port so they can run all of these compatible boards. Some might even support more than one lane eventually.