I very much doubt if Edward VII purchased 27 tiaras.

There is nothing in Hans Naddelhoffer's history of Cartier, or any other history of Cartier that I have seen, about the King buying numerous tiaras, much less 27!

There are several biographies of Edward VII but I don't think any have even hinted at that number of purchases.

Edward VII & Queen Alexandra were clients of Cartier. I think that most of their major purchases have been identified by now.

So often people write things or make videos without trying to check the facts.

If tiaras are worn by ladies at the forthcoming coronation, I have no doubt some will have been made by Cartier, but was the person who purchased them Edward VII?? I would like to see some verifiable evidence.