Sorted all parts purchased from Digikey, Mouser and Aliexpress, the first step is to solder the connectors which will help the hardware debug. Importantly, to test voltages after the line filter in different points and ensure no short circuits or open connections.

Separately, a complete ECS chipset is tested ready to be installed afterwards.

Fortunately, KiCAD can generate the interactive BOM list and the visualisation is tremendously helpful to ensure a fail-safe process.