Hi,
"EPCS4" is in the file because it's generated for EPCS4.
Seriously I don't fully understand your question. You have sucessfully verified programming and configuration operation with W25X40 and are asking if it can be really used?
According to my experience Winbond serial flash are fully compatible to Intel devices for AS configuration. In some cases, it might be necessary to disable ID check in .jic file generation. With direct AS programming, the only relevant criterion is that the programmer programs and verifies the configuration file.
Regards,
Frank