There are several other OS BIN files that have valid, well defined, nicely-featured XDF files for 5.3 liter vehicles with 4L60E transmissions. Simply abandon 12579405 and go for a completely different tune for a 5.3 / 4L60E. I'm running several different here:

12208322

12212156

12202088

As best that I can tell, 12579405 has no associated XDF.

Rick