Please see the documentation for DNG profiles, Camera Raw, and Photoshop.
I have. Many times. Burned many hours over it.
And there's a trivial demonstration for why it's useless to even pretend to attempt a colorimetric workflow with Adobe products. To the best of my knowledge, not a single vendor sells _any_ product for building DNG profiles with anything other than a 24-patch ColorChecker, and those products that support a ColorChecker don't let you provide your own measurements for the chart nor SPD information for the actual illuminant the chart is photographed under.
Are you pretending that the capabilities don¹t exist simply because you can¹t buy a commercial tool to exercise those capabilities? That is insane. Just because you cannot buy a screwdriver that you like, does not mean that the screws don¹t exist or work, or that other people don¹t have screwdrivers which they like and work for them.
Adobe makes great products for certain types of artistry. But attempting to use Adobe products for anything where colorimetric accuracy is an essential part of the workflow is as insane as attempting to use a Lamborghini to sow crops or racing a farm tractor in Le Mans.
You seem to apply your misunderstandings of DNG to all Adobe products and operations (even those that don¹t deal with DNG or Camera Raw). That is also more than a little insane. You may have issues with one particular method of input - but that in no way affects the rest of the applications or their capabilities. You would do far better to ask questions on this mailing list instead of making such ludicrous claims. I¹m sure that other folks on the list could help you understand your misunderstandings and mistakes. Chris