[Moto G5S Plus Guides, News, & Discussion] internetpilot:
Thank you for this. A huge thank-you for mentioning that you don't necessarily need to erase userdata. I've been running modified/rooted stock v7.1.1 all along, and really didn't feel like reinstalling apps and reconfiguring everything without the help of Titanium Backup, etc. (because I wouldn't have root). And skipping that line worked perfectly!

Some things to note about the process (at least for XT1806 Retus and SANDERS_NPSS26.116-48-18_cid50_subsidy-DEFAULT_regulatory-DEFAULT_CFC) as well as the subsequent Oreo 8.1 update:

There is no system.img_sparsechunk.6 so don't freak when entering that line gives you an error. Initially I was worried it was a zip corruption issue, but it's just not included for this version of Retus.

You'll get a "bad key" message when flashing the boot.img and recovery.img. It doesn't error out or not flash, but the error message can be a little alarming.

The initial boot of the June 1, 2018 firmware stalls the Lenovo logo screen for quite a while, and then even after the boot animation starts, it still takes quite a while. I was worried this was due to encryption issues and was regretting not deactivating the PIN, but it eventually booted and everything was fine. I would estimate at least a solid 5 mins for that first boot, though, which can be a bit scary if you're a little uneasy about this whole process.

After booting to June 1, 2018 7.1.1, it was running for all of maybe 2 mins before the Oreo 8.1 OTA update popped up. FYI, the install of the update stalled at like 30% for at least 15 mins, then after slowly getting to maybe 40% it made an instant jump to like 90%. Again, very scary for anyone a little uneasy about how all this is going to turn out. The whole install process taking about 20 mins.

The first boot of the Oreo 8.1 update was just like the first boot of the June 1, 2018 7.1.1. firmware both in the amount of time and what was on the screen.

Immediately after successfully booting Oreo 8.1 I received 3 security updates in row. Installing and booting these was MUCH faster (basically like a normal reboot).

I run Nova Launcher Prime and the Oreo update messed up my wallpaper for my home screen (it defaulted to an Oreo wallpaper). My lockscreen wallpaper remained the same. When I tried to change the home screen wallpaper (through Nova Launcher or through the settings menu), it wouldn't stick/change. Eventually, I went into Nova Launcher settings, didn't seen anything that needed changing so I exited, and the wallpaper reset to what I wanted. So it appears to be a glitch in Nova Launcher that is resolved by simply enter and exiting Nova Launcher settings.

I thought for sure I would simply re-root after receiving all the current OTA updates. I "needed" to do that in order for the Google Camera app's HDR+ to work, but as it turned out, the Google Camera works as it always has even after the Oreo update. However, my wifi hotspot no longer works. So, clearly my original build.prop mods didn't survive the flashing/updates, but apparently the camera2 api is already activated in the Oreo 8.1 update. Not entirely sure...?

I'll edit my build.prop again (without rooting by fastboot booting TWRP) and see what happens, but that doesn't have anything to do with this process. I hope my observations above helps anyone feeling uneasy about the process (like I was).

Thanks again!