Apps audit is only for PPR (see v2.3 announcement), in which case you would have an actual personal peristent repository, i.e., tce directory specified as a boot option.
A PPI does not have or even require such repository. A PPI is a hybrid scatter mode installation, where tces or, starting with v2.3, tczs are untarred over a mounted hard drive parition. No such collection of tce abnd or tczs need to be saved. In fact, as you noted, in a PPI, the default tce directory is /tmp/tce and are removed after installation.