Keep the aux, fls and log files or not?

I have a C program generating a .tex file. Then afterwards the C# program runs Pdflatex to compile to pdf and generates an .aux , .fls and a .log file.

The tex file is different (in priciple) each time I run my C# program because of different input values.

Is there an advantage in keeping the aux and/of fls file after each compilation?

Or: are they ever helpfull in new compilations?