Payment of Foreign Inheritance Tax

Various articles on Lexis Nexis indicate that the presumption that a direction to pay inheritance tax (or testamentary expenses) does not include foreign inheritance tax has lost most of its force as the case of Re Goetze means that, to the extent payment of foreign tax acts as a corresponding credit towards payment of UK tax, the foreign tax still needs to be paid from residue as, if it is not, then the specific foreign legacy is not free of UK tax. Do others agree with this interpretation of law? From reading Re Goetze, it seems a logical conclusion but a very odd one, and I see no reference to this in WM&S.