[Samsung Galaxy S9 & S9+ (Snapdragon) ROMs, Kernels] desudecchi:
Yes, the bootloader is unlockable. I'm currently the guinea pig for Travis and helping out as much as I can.

Edit: Root has been achieved (took too long trying to find the winning combination for this phone)!

Edit 2: ls -l /dev/block/platform/soc/1da4000.ufshc/by-name/ = no such file or directory.

Found a change in the file: 1da4000.ufshc -> 1d84000.ufshc

ls -l /dev/block/platform/soc/1d84000.ufshc/by-name/ <
total 0
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 abl -> /dev/block/sdd8
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 aop -> /dev/block/sdd5
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 apdp -> /dev/block/sdd15
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 apnhlos -> /dev/block/sda16
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 bksecapp -> /dev/block/sdd11
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 bluetooth -> /dev/block/sdd10
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 boot -> /dev/block/sda20
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 bota -> /dev/block/sda10
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 btd -> /dev/block/sdd25
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 cache -> /dev/block/sda25
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 cmnlib -> /dev/block/sdd13
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 cmnlib64 -> /dev/block/sdd14
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 ddr -> /dev/block/sdd1
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 debug -> /dev/block/sda28
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 devcfg -> /dev/block/sdd19
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 devinfo -> /dev/block/sdd9
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 dpo -> /dev/block/sdd17
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 dqmdbg -> /dev/block/sda14
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 dsp -> /dev/block/sda18
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 dtbo -> /dev/block/sda19
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 efs -> /dev/block/sda6
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 em -> /dev/block/sdd23
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 fota -> /dev/block/sda11
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 fsc -> /dev/block/sda3
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 fsg -> /dev/block/sdd3
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 hidden -> /dev/block/sda26
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 hyp -> /dev/block/sdd4
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 keymaster -> /dev/block/sdd12
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 keystore -> /dev/block/sda9
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 limits -> /dev/block/sdd18
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 misc -> /dev/block/sda8
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 modem -> /dev/block/sda17
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 modemst1 -> /dev/block/sda1
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 modemst2 -> /dev/block/sda2
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 msadp -> /dev/block/sdd16
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 nad_refer -> /dev/block/sda15
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 odm -> /dev/block/sda24
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 omr -> /dev/block/sda27
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 pad -> /dev/block/sdd26
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 param -> /dev/block/sda7
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 persist -> /dev/block/sda5
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 persistent -> /dev/block/sda12
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 pmic -> /dev/block/sdd7
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 qupfw -> /dev/block/sdd22
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 recovery -> /dev/block/sda21
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 sec -> /dev/block/sdd6
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 ssd -> /dev/block/sda4
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 steady -> /dev/block/sda13
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 storsec -> /dev/block/sdd20
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 system -> /dev/block/sda22
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 tz -> /dev/block/sdd2
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 userdata -> /dev/block/sda29
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 vbmeta -> /dev/block/sdd21
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 vendor -> /dev/block/sda23
lrwxrwxrwx 1 root root 16 2018-01-26 23:38 vk -> /dev/block/sdd24
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 xbl -> /dev/block/sdb1
lrwxrwxrwx 1 root root 15 2018-01-26 23:38 xbl_config -> /dev/block/sdb2

blkid:

/dev/block/loop0: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/vnswap0: LABEL="swap" UUID="b19377ca-7847-4917-e5f4-8f9ee546b7c1" TYPE="swap"
/dev/block/sda5: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda6: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda14: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda15: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda16: SEC_TYPE="msdos" UUID="00BC-614E" TYPE="vfat"
/dev/block/sda17: SEC_TYPE="msdos" UUID="00BC-614E" TYPE="vfat"
/dev/block/sda18: LABEL="dsp" UUID="af32c008-2a39-7e5b-a5dc-201456d93103" TYPE="ext4"
/dev/block/sda22: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda23: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda24: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda25: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda26: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/sda27: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"
/dev/block/mmcblk0: UUID="E279-356D" TYPE="exfat"

/sys/class/android_usb/android0/f_mass_storage/lun0/file = I can get to f_mass_storage and these are the following files and folders:

device (folder)
inquiry_string (file)
power (folder)
product_string (file)
sua_version_info (file)
subsystem (folder)
uevent (file)
vendor_string (file)

All folders don't have lua0/file... in /android0 there is a file called bcdUSB. I don't know if that might be what you are looking for.