I am a rather advanced user, testing /e/ with a Sony Xperia XA2 phone. It looks like there is no support of F2FS in /e/'s kernel, is there?
/e/ appears to be using ext4 for its main file systems, and it also fails to automount an F2FS-formatted SD card. Trying to manually mount it from the command line also fails, and the content of /proc/filesystems does suggest that it does not include the f2fs driver.
Is there a reason to not include the f2fs Linux driver? If it was not never considered, it would be a good idea to include it, and maybe to use F2FS for the main file systems, because it is more suitable to flash-based devices, and it actually beats ext4 in benchmarks.