Opening a container costs ~4 s and the iteration count belongs to the desktop format, so the fix is to stop repeating it: derive once per snapshot, then read a local AES file which the hardware accelerates. The key is generated inside the Keystore and never leaves it - the file alone is useless, even rooted.
ETag and vault are encrypted together on purpose: an ETag outliving an unreadable vault would make the server answer 304 with nothing to show. A failed read wipes the cache rather than guessing.
Also normalises every Delphi source to pure ASCII: Delphi reads a BOM-less file as ANSI, so accented comments came back as mojibake, and each PowerShell rewrite added another layer.