I use the last nightly (1411) and follow the instruction from How to use the Team CoreELEC ceemmc tool to install CE only on the emmc. Thanks you for this Portisch !
CoreELEC:~/backup # dmesg | grep mmcblk
[ 4.414046@2] mmcblk0: emmc:0001 S0J38Y 58.2 GiB
[ 4.418569@2] mmcblk0boot0: emmc:0001 S0J38Y partition 1 4.00 MiB
[ 4.424646@2] mmcblk0boot1: emmc:0001 S0J38Y partition 2 4.00 MiB
[ 4.430703@2] mmcblk0rpmb: emmc:0001 S0J38Y partition 3 4.00 MiB
[ 4.452523@2] meson-mmc: [mmcblk0p01] bootloader offset 0x000000000000, size 0x000000400000
[ 4.461879@2] meson-mmc: [mmcblk0p02] env offset 0x000000400000, size 0x000000800000
[ 4.471181@2] meson-mmc: [mmcblk0p03] misc offset 0x000000c00000, size 0x000000800000
[ 4.480538@2] meson-mmc: [mmcblk0p04] logo offset 0x000001400000, size 0x000000800000
[ 4.489954@2] meson-mmc: [mmcblk0p05] dtbo offset 0x000001c00000, size 0x000000800000
[ 4.499311@2] meson-mmc: [mmcblk0p06] reserved offset 0x000002400000, size 0x000004000000
[ 4.508679@2] meson-mmc: [mmcblk0p07] CE_FLASH offset 0x000006400000, size 0x000020000000
[ 4.518033@2] meson-mmc: [mmcblk0p08] CE_STORAGE offset 0x000026400000, size 0x000e69400000
[ 6.869187@0] EXT4-fs (mmcblk0p8): couldn't mount as ext3 due to feature incompatibilities
[ 6.999953@0] EXT4-fs (mmcblk0p8): mounted filesystem with ordered data mode. Opts: (null)