I recently bought a Moto G4 .... Coming from a Nexus 4 with CM i never bothered to use Magisk instead of the old default root+xposed instaled into system... But because Motorola locks a lot more the device than a Nexus, i tried to used Magisk + Xposed systemless.... And i bumped into a problem....
After unlocking the bootloader (while using 100% stock rom), if i enter at the bootloader mode in the device a message indicates that my G4 is unlocked, but running official software... If i try to install SuperSu systemless everything goes OK, and the smartphone keeps showing that the software is official (even after SuperSu modified the boot image, which is a necessary step to achieve the systemless root)...
So i thought that Magisk + Xposed Systemless would work the same way... After Magisk instalation, the message keeps being "Software Official" ... But as soon as i install Xposed Systemless, and reboot the device once, then immediately the message changes to "Software Modified" and i am unable to do any OTA update...
So i'm confused: SuperSu and Magisk both modify the boot image from the G4.... But why SuperSu is capable of modify it and the system doesn't see any change, but Magisk + Xposed modify it but aren't able to prevent the change detection as SuperSu does?
To add one more info: as i said, because Magisk + Xposed Systemless make changes at the boot image that are detected by the ROM, the phone status is changed from "Software Official" to "Software Modified", breaking any OTA updates... But if i re-flash the stock boot image, the OTA updates are able to be instaled again. (but then i lose SuperSu, Magisk and Xposed Systemless)
My main question: if SuperSu can patch the boot image to work, and that change is invisible to the smartphone, allowing me to do OTA updates, why Magisk + Xposed Systemless don't use the same technique ? I'm guessing that the technique is different because , like i said, the patched boot image from Magisk + Xposed is detected as altered, while installing SuperSu only doesn't generate any problem to the OTA updates...
In the actual scenario, at least for a Moto smartphone, the Magisk + Xposed Systemless aren't actually "systemless" .... Ok, they don't change the system image, but change the boot image, which leads to blocked OTA installation (because of the SOFTWARE MODIFIED status that checks the boot image, sees the alterations and stops the update), and at the end it acts as a system modification when anyone tries to update a Moto phone wiht Magisk + Xposed Systemless installed...