I don't believe that the WLE600VX or WLE900VX are capable of dual-band, simultaneous operation. It's been a while, but that's my recollection.
https://wikidevi.com/wiki/TP-LINK_EAP225_v3.x
I recall the discussion on IRC indicating that it was a 16 GB flash (Edit: Yes, see below)
15:54 mvnetbiz: so wiki says this has 8MiB of flash, but /dev/mtd seems to say 16MiB
15:55 mvnetbiz: init mtdparts=spi0.0:128k(u-boot),64k(pation-table),64k(product-info),1536k(kernel),14336k(rootfs),192k(config),64k(ART) mem=128M board=AP152
On the Compex cards, see, for example Best Wireless AC router for LEDE? - #24 by shdf and following.