File system of Android 10 running devices
according to this TWRP the Samsung Galaxy A30 SM-A305F is shipped with Android 9.0 (Pie) FDE full-disk-encryption
BoardConfig.mk
# Filesystem
TARGET_USERIMAGES_USE_EXT4 := true
TARGET_USERIMAGES_USE_F2FS := true

The file system type depends on ROM and can be F2FS or EXT4