DY: What stops the husband from showing up to court and the Bais Din Paskening that a Get should not be given? I don’t see the issue as “withholding a Get”, but rather the (related) issue of husbands not showing up to court to be judged.
IMHO, if the husband is just holding out for more money/rights, then the Bais Din will (appropriately) Pasken that a Get must be given. If he really believes that there is still a chance at keeping it alive (and Bais Din agrees), and she just doesn’t want to, she will be Paskened as a Moredes and will lose the support (via the Bais Din).