Incorrect dash vin tag

So what we have established is if you have a VIN tag suspended in free space you can attach all the needed sheetmetal to it. But you can not take the same Vin tag and attach it to the needed sheetmetal.

Where is the distinction?

Take a core support and bolt / weld other parts to it that's fine

Bolt or weld a core support to other sheetmetal that's not good.