I still don’t understand, why “developer-tested” is relevant, whereas “[vendor-tested]” isn’t.
By using Qubes OS and being part of this community I am implicitly and explicitly placing a huge amount of trust in Marek and the development team. There is just no helping it. If I don’t trust them, I might just as well use Windows. Of course it is relevant which computers they are using to test Qubes OS. Naturally bugs will be found and fixed on those machines first. Note that this has nothing whatsoever to do with Lenovo or placing any trust in them.
On the other hand, all I ever heard about Purism so far is: they got certified and then the certification needed to be removed because of hardware changes. @Michael was open to restart the process with them and aborted it again because he got reminded how Purism “as a company” works. All this does NOT imply bad intent on either side, but that at least one side is more or less flying by the seat of their pants. Which might be OK in some circumstance, but not to certify hardware. So this is explicitly NOT about trust. Nobody here thinks that Purism is malicious as far as I can tell. They have just decided to develop hardware in a way that does not work well with getting certified.
Qubes OS doesn’t even come preinstalled and all we have is one sentence on their website saying that they test their hardware to work well with Qubes OS (which version?, how often?, what process?). To consider a “vendor-tested” comment at the very least there would need to be a dedicated page on their website showing which version of Qubes OS was tested against which version of their hardware and with which result. And what “tested” means in the first place: what was tested … just that it installs?
That’s why community submitted HCL reports offer much more insight and confidence than a vendor claiming to test their hardware on their website. Makes sense?