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The one issue I see is that at least for the homepage, these two sites are identical. You have so many different geo-target sites, but between two sites of the same language regardless of location, does anything change? I'm seeing no differences on the homepage so I need to ask. This might be part of why .be is cached for .nl, you're not giving them something new to index. They are hreflang'd as well, which is telling them even more that the content is the same. I am going to assume that .be launched before .nl, or has gotten more play in the search results. Something is making it the go to for Dutch.

I would love to see any of it you are willing to share. I am not saying in any way it is an absolute (what is in SEO?), I just worry over not indexing a page for mobile. Best