Is there a guide to enabling PiAware to act like a Stratux?
Just use the Statux software
The changes in dump1090-fa 4.0 allow it to be used as part of a Stratux install, as requested/contributed by some of the Stratux maintainers (see https://github.com/flightaware/dump1090/pull/61). That is, it allows Stratux to use dump1090-fa for 1090 reception rather than the older version it originally used.
The Stratux-format output is not used by piaware and there is no Stratux/piaware integration.