May I interject that the reality of the alleged transfers from Flanders to Wallonia is dubious at best. Sure, by considering an ideologically motivated subset of all financial streams in a country it's perfectly possible to come up with numbers that indicate such. Those are the numbers one finds all over nationalistic propaganda websites.
But actual scholarly studies of the matter tend to be very cautious about this. The complexity of the Belgian state leads thereto that one has to repartition certain financial assets which are not uniquely attributable to any of the communities at the hand of arbitrary parameters. It's pretty easy to tweak these parameters in your favour to make the end result correspond with the desired political outcome. But there is no rational ground for putting the parameters at these values.
The reality of the matter is that Belgium, despite the linguistic divide, is pretty much a centralized country with the influence of Brussels stretching well into both Flanders and Wallonia. It's not at all comparable with e.g. Czechia and Slovakia which each have their own centers around which a divided set of 'countries' can be built up. Brussels' position in Belgium is much more comparable with e.g. Paris in France.
I challenge any nationalist to come up with a rational and realistic plan for dividing such a country. It's pretty easy to make this claim in an election campaign with a media that never asks any awkward questions but none of these nationalist and populist parties has ever presented a plan that it is not purely ideological but pragmatic.
It's no accident that De Wever's tone changed instantly after his victory. The man fully realizes that any negotations over a divide of Belgium would be a thousand times more difficult than the trivial matter of BHV which already leads to an impasse. There is no plan.