Field note
When catalog is faster than custom
A custom carrier is a real project. Most teams need a known card, three I/O deltas, and a date.
9 December 2025
Custom feels like control. It is also a schematic, a layout, a fab cycle, and a second safety review. If a catalog SBC already has the lanes you need, take it. Spend the calendar on your application.
Modified COTS is the honest middle: keep the PCB, change the connector mix or the coating, freeze a BOM. Full custom is for envelopes that do not exist — rare, expensive, and worth it only then.