Answer
No, and it isn't planned for Aurena or future IFS Cloud releases either — this is a deliberate design decision, not a current gap waiting to be filled. Aurena's equivalent of a custom command/button is a Custom Action added to a projection, but it always requires referencing an actual PL/SQL method that's been deployed in the database first; there's no way to embed raw PL/SQL logic directly into a projection/page configuration the way EE's PL/SQL Block custom menu type allows. This is explicitly because of security concerns around letting arbitrary PL/SQL be written and run directly from the client — concerns that already existed around the EE PL/SQL Block mechanism itself, which is exactly why the equivalent capability was deliberately excluded from Aurena and isn't expected to be added later.