It seems some browsers have a set of rules to try to detect & at least highlight domain typosquatting. So it would seem there are ways to do that by looking at character substitutions, etc. Anyway, I think it would be a great aspect to be able to have the router block against, since typo-squatted domains are usually not something one wants users to visit since they are usually scam websites of some type.
Here’s a recent article on the type of typo-squatting that apparently Chome can detect & highlight.
Two characters open up a world of typosquatting opportunities in Chromium browsers