I just ran across your question. I have the same question for the CYW943907AEVAL1F eval board: How to Use SPI Flash for General Storage? (CYW943907AEVAL1F)
My tests indicate that APP DCT on this eval. board is limited to ~ 4kB (not very much), but a great deal of memory is free in the SPI Flash. That would be the place to store larger amounts of data without having to add another external memory device (SPI or I2C).