ArM5 p.189 has: "There are two ways to enter a regio voluntarily, and either or both may apply to a particular regio. The first involves seeing into the regio and then crossing the boundary. This
requires some supernatural ability. <snip> The second way of entering involves following a particular path or ritual. <snip> At least one of these methods of entry must apply to any regio, at least if it is to have any impact on the game."
ArM5 p.158 Piercing the Divine/Faerie/Infernal/Magic Veil provides the first way and references ArM5 p.189: so it does not override p.189, and does in general not allow to enter regios accessible only via the second way.