Here is the guide I’ve used to install Android 9 (pie), TWRP and root (using Magisk). That guide is pretty accurate, though SuperSU v2.82 SR5 (the latest I could find) didn’t work. Instead Magisk v18.1 does work for rooting :).

Device: Samsung Galaxy A8 (2018), SM-A530F.

Here is a list of software (and version numbers) that works for me:

• MagiskManager-v7.0.0.apk
• Magisk-v18.1.zip
• no-verity-opt-encrypt-6.0.zip
• PHN-A530FXXU4CSC6_A530FOXM4CSC6-20190314.zip (🇳🇱 no carrier)
• RMM-State_Bypass_Mesa_v2.zip
• twrp-3.2.3-0-jackpotlte.img.tar

Optional for unrooting:

• UPDATE-unSU-signed.zip

Too bad JOdin didn’t recognize the phone, and I had to use Odin on Windows:

• Odin3_v3.13.1.zip
• SAMSUNG_USB_Driver_for_Mobile_Phones.exe

I’ve had no issues with ‘missing OEM unlock toggle‘ (and having to wait seven days to unlock). Hope this helps to quickly setup Android 9, TWRP and to unlock the phone. Have fun, all credits go to the devs at XDA.