[Xiaomi Redmi 5 ROMs, Kernels, Recoveries, & Other ] vetzki:
for treble support only different fstab and BoardConfig parameter needed (at least I think so),

diff --git a/BoardConfig.mk b/BoardConfig.mk
index ce63750..c631a53 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -90,3 +90,7 @@ TW_THEME := portrait_hdpi

# Disable Mouse Cursor
TW_INPUT_BLACKLIST := "hbtp_vm"
+
+# Treble
+BOARD_NEEDS_VENDORIMAGE_SYMLINK := false
+TARGET_COPY_OUT_VENDOR := vendor
diff --git a/twrp.fstab b/twrp.fstab
index a581921..97dad11 100644
--- a/twrp.fstab
+++ b/twrp.fstab
@@ -3,15 +3,45 @@
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

/system ext4 /dev/block/bootdevice/by-name/system flags=display="System"
-/data ext4 /dev/block/bootdevice/by-name/userdata flags=length=-16384
+#/system_image emmc /dev/block/bootdevice/by-name/system flags=backup=0;flashimg=1
+/system_image emmc /dev/block/bootdevice/by-name/system flags=flashimg=1;display="Image system partition"
+#/data ext4 /dev/block/bootdevice/by-name/userdata flags=encryptable=footer;length=-16384
+/data ext4 /dev/block/bootdevice/by-name/userdata length=-16384
+/data_image emmc /dev/block/bootdevice/by-name/userdata flags=backup=1;display="Image data partition"
+/boot emmc /dev/block/bootdevice/by-name/boot flags=display="Boot"
/cache ext4 /dev/block/bootdevice/by-name/cache flags=display="Cache"
-/cust ext4 /dev/block/bootdevice/by-name/cust flags=display="Cust";backup=1
+/storage ext4 /data/media/0 flags=display="Internal Storage";usermrf;backup=1;fsflags="bind";removable
+/vendor ext4 /dev/block/bootdevice/by-name/cust flags=display="Vendor";backup=1;wipeingui
+/vendor_image emmc /dev/block/bootdevice/by-name/cust flags=backup=0;flashimg=1
+
/recovery emmc /dev/block/bootdevice/by-name/recovery flags=display="Recovery";backup=1
-/boot emmc /dev/block/bootdevice/by-name/boot flags=display="Boot"
/misc emmc /dev/block/bootdevice/by-name/misc flags=display="Misc"
-/efs1 emmc /dev/block/bootdevice/by-name/modemst1 flags=display="EFS";backup=1
-/efs2 emmc /dev/block/bootdevice/by-name/modemst2 flags=backup=1;subpartitionof=/efs1
-/firmware vfat /dev/block/bootdevice/by-name/modem flags=display="Firmware";mounttodecrypt
/persist ext4 /dev/block/bootdevice/by-name/persist flags=display="Persist";backup=1
+/persist_image emmc /dev/block/bootdevice/by-name/persist flags=backup=0;flashimg=1
+/splash emmc /dev/block/bootdevice/by-name/splash flags=display="Boot Logo";backup=1;flashimg=1
+
/sdcard1 auto /dev/block/mmcblk1p1 flags=display="MicroSD";storage;wipeingui;removable
/usb-otg auto /dev/block/sda1 flags=display="USB Storage";storage;wipeingui;removable
+
+# Bootloader
+/aboot emmc /dev/block/bootdevice/by-name/aboot flags=backup=1;display="Bootloader"
+/cmnlib emmc /dev/block/bootdevice/by-name/cmnlib flags=backup=1;subpartitionof=/aboot
+/tz emmc /dev/block/bootdevice/by-name/tz flags=backup=1;subpartitionof=/aboot
+/rpm emmc /dev/block/bootdevice/by-name/rpm flags=backup=1;subpartitionof=/aboot
+/keymaster emmc /dev/block/bootdevice/by-name/keymaster flags=backup=1;subpartitionof=/aboot
+/devcfg emmc /dev/block/bootdevice/by-name/devcfg flags=backup=1;subpartitionof=/aboot
+
+# Modem backup/restore
+/firmware vfat /dev/block/bootdevice/by-name/modem flags=display="Firmware";backup=0;mounttodecrypt;fsflags=ro
+/modem emmc /dev/block/bootdevice/by-name/modem flags=display="Modem (Image)";backup=1;flashimg=1
+/dsp emmc /dev/block/bootdevice/by-name/dsp flags=backup=1;subpartitionof=/firmware
+/sec emmc /dev/block/bootdevice/by-name/sec flags=backup=1;display="Sec"
+#/config emmc /dev/block/bootdevice/by-name/config flags=display="OEM";backup=1
+#/sec emmc /dev/block/bootdevice/by-name/sec flags=display="Sec";backup=1;subpartitionof=/config
+
+
+# EFS backup/restore
+/efs1 emmc /dev/block/bootdevice/by-name/modemst1 flags=backup=1;display="EFS"
+/efs2 emmc /dev/block/bootdevice/by-name/modemst2 flags=backup=1;subpartitionof=/efs1
+/efsg emmc /dev/block/bootdevice/by-name/fsg flags=backup=1;subpartitionof=/efs1
+/efsc emmc /dev/block/bootdevice/by-name/fsc flags=backup=1;subpartitionof=/efs1

(note: not all partitions needed, e.g. efs, bootloader, _image stuff)

built recovery but didn't test anything beside backup and flashing xiaomi.eu rom

but do you need such a recovery to install los-15.1 ?