>>A fairly simple solution. A cap on inherited wealth.
Perhaps apart from one home? Sure that will lead to family wealth concealment in grand palaces- but those stately manors in the UK require a lot of upkeep and are worth preserving. Last time, probate duty caused more than a few such houses to be demolished or to fall into ruin and that's already a risk today for many of these homes, even without more tax. These days it's more likely the properties would be transferred to foreign oligarchs immune to the tax.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1