There is a difference between mass production and inventing.
Gavilar or someone close to him created Anti-Voidlight and Navani actually saw this and used it to get what she was looking for.
Also creating the Anti tone wasn’t hard. She saw in a book Destructive Interference and she used Intent.
The hard part was making that come together with Voidlight which didn’t take her to long only 2 weeks max and probably not that.
In the end she made an easily repeatable and accessible process building off the work of others, which is completely fine and worthy thing.
But does it make her deserve lots of credit? She will get some yah but it will be mostly undeserved, the credit for Anti voidlight lies solely on Gavilar and Co
Im going to give an example here: please don’t analyze it to much and fact check it
Thomas Edison invented the lightbulb he was the first one to do it and got all the credit.
If someone at the same time across the world came up with the light bulb immediately afterwards all by themselves they would receive nothing. End Example
So Navani only gets credit for the mass production not the product