Custom ROM flashing workflow

[Totesnochill]

I'm planning to upgrade from Nokia x6 to Nokia8.
On x6, I really liked the nice and clean custom rom installation workflow of:

1. Unlock Bootlader
2. fastboot boot twrp.img
3. In TWRP, backup the stock everything, upload to PC
4. In TWRP, wipe everything and flash customRom.zip
5. (IF something failed) In TWRP, restore backup to bring phone to 100% original state.

Does Nokia 8's workflow differ much? I've read the guide , but still unsure. From what I could see in 8.1 threads, the new bootloader does not support "fastboot boot" command, meaning the first time flash will be destructive (i.e. will wipe the stock without an option to backup partitions first)