Agree with you @itswinetime, Kate needs to wear a different tiara.
However just read this article on Royal tiara etiquette and Tiaras are a lifetime loan, and no other lady gets to wear them. (Although I’ve seen an exception with Princess Anne wearing the Queens wedding tiara on her wedding day)
I’ve also seen the Lotus flower tiara on both the QM and PM.
So Kate actually has 3 tiara’s at her disposal; her wedding day scroll tiara, the lotus flower and the Cambridge lovers knot.
So if Meghan ever goes to a tiara event; we should see her wedding day tiara again.