I've been researching https://schema.org/SiteNavigationElement markup and there's a lot of conflicting information out there as to its value.
Some people are suggesting if you define this data in your pages it can influence what Google shows for site links, however others are not so sure.
My feeling so far is that it can't hurt to define my top six most important links, which in my case would be level 1 categories in my eCommerce site. However, in doing so, I'm assuming this would only included behind the scenes on my home page?
The other interesting question I have with this element is that Google doesn't list it under its Featured Guides (such as this Product example ~ https://developers.google.com/search/docs/advanced/structured-data/product) which may suggest its of little relevance these days.
It would be good to be able to define site links like we used to be able to in tools such as Google Search Console, is this going to assist?