Petit FatFs R0.03a has been released at January 30, 2019. These are the verified problems about Petit FatFs R0.03a and its workaround or patch.
1. May 20, 2021 ------------------------------------------------------------------------------ a. Broken extended character conversion table for CP857. b. Compiler waning when FAT32 is disabled. To fix these problems, apply pff3a_p1.diff to pff.c.