Adventures in BP installation (12.1.0.2.180417)

Installing BP 180417 (both DB and OJVM) on Windows 2012 with Oracle 12.1.0.2 Std Ed TWO.

Installation currently has the following:

SQL> select PATCH_ID,  2          ACTION,  3          ACTION_TIME,  4          DESCRIPTION,  5          STATUS,  6          BUNDLE_SERIES  7  from registry$sqlpatch  8  order by 1;  PATCH_ID ACTION          ACTION_TIME                    DESCRIPTION                                   STATUS     BUNDLE_SER---------- --------------- ------------------------------ --------------------------------------------- ---------- ----------  26161726 APPLY           03-MAY-18 10.27.06.080000 AM   WINDOWS DB BUNDLE PATCH 12.1.0.2.170814(64bit SUCCESS    PSU                                                          ):26161726  26182439 APPLY           03-MAY-18 10.27.05.674000 AM   WINDOWS ORACLE JAVAVM COMPONENT BUNDLE PATCH  SUCCESS                                                          12.1.0.2.170718 (64bit): 26182439

Test bed is a VirtualBox VM that is backed up to current status, so can easily be reset for repeating tests.

I learned from previous threads and tests that the JAVAVM patch would need to be de-installed before installing either of the 180417 patches. First test went well but there were some discrepancies between the installation 'readme' docs and reality.  On trying to repeat and correct, the step of running datapatch immediately after the opatch rollback of the JAVAVM patch, datapatch returned ORA-20001: Latest xml inventory is not loaded into table'.  This lead to