It’s really about assumptions, and what gets put where. INT was felt to be fairly likely to have been ‘properly’ done. BAK and FRT are more likely to be messier. Which will lead to unexpected output in your PDFs.
If there is no text that’s outside a periph section, and all the periph sections have been properly flagged with id="something"
, then the following ought to work:
\StoreAllPeriphstrue
\ptxfile{A0FRTproject}
\ptxfile{99BAKproject}
\StoreAllPerphsfalse