I think I really am limited to queryParams. This post shows how to do it: Ionic 4 Tab navigation params.
However, I am still having an error every time I try to implement ion-tabs (the missing chunk) It seems like a router issue though… not related to tabs at all.
In fact, this is an error with the way I lazyliad the route (will investigate later). Here is a good article to understand lazyloading. (The error I get is related to a chunk, and lazy loading creates a new chunk, so the error is most likely due to the lazy load. It is weird that the page works fine if I replace the tabs by anything else though)