For the sake of clarity, the threading on the Vivaldi is M4. The threading on the Stillpoints Ultra is ¼-20. They are not the same. My use of the two measurements together was a reference to the Stillpoints adapter that permits the use of the Stillpoints with the Vivaldi. And it has worked flawlessly with all three of my Vivaldi boxes. But other third party feet might have different attachment methods and hardware sizes. I also take James’ warning about shank depth seriously. Stillpoints supplies this data about their adapters, and as James notes, it’s easy to measure the shank depth on the OEM screws.
I’m not sure this is an apt or fair comparison. Assembly instructions include a bill of materials so as to make sure that the necessary components are there for the purchaser to complete assembly. If dCS sold their components unassembled, such a bill would be expected. But they don’t. And I certainly don’t expect them or any other finished equipment maker from whom I purchase to supply me a BOM of all hardware that goes into the item.
Granted, one might be inclined to put replacement footers in that category of “Things You Might Want to Change,” à la power cords and digital/analog interconnects. But I rarely see other high end makers do this. But I admittedly haven’t been looking.