[General Questions and Answers] Tzul:
[MENTION=1748680]lacostej[/MENTION] You can certainly automate some steps, and you do not always need root. (And the best way to root is to install the latest SuperSU via TWRP; no need for questionable apps that are doing who knows what...)

There are three ways to install another firmware:

The MediaTek SmartPhone Flash Tool (SPFT). This is a PC program (Windows and Linux) that allows reading and writing of the entire internal storage (on a partition granularity). Via USB, while the device is powered down. Only for devices based on MediaTek chips, of course (this tablet is MediaTek-based).

Fastboot. This is a little USB protocol implemented by the bootloader. A Fastboot client on PC can communicate with the bootloader via USB and execute certain commands, e.g. "fastboot flash" for flashing partitions. However, there are a few drawbacks with this:

First, you need to boot the device into fastboot mode. Some devices have a boot menu that allows you to do this, but this device doesn't. Starting the tablet via power+volumeUP takes you directly to the recovery instead of a boot menu. But in the recovery, whether stock or TWRP, there's a reboot to bootloader option. Using ADB (adb reboot bootloader) should also take you there.

Second, the "fastboot flash" command is restricted on this tablet. If you were to use "fastboot flash recovery <recoveryfilename_here>", for example, it would abort with an error message. I have patched the bootloader to allow the flash command, but you'd first need to install this patched version on your tablet(s), of course, via SPFT or other means.

Third, the "fastboot flash" command has a size limit - the bootloader needs to buffer the USB data in RAM before it can be written, and since the tablet has only 1 GB of RAM, you obviously can't flash a 1 GB system image this way. The buffer is actually a lot smaller: just 128 MiB. Meaning whatever file you send to the tablet via "fastboot flash", it cannot be larger than 128 MiB. So, how do you flash the system or userdata partition then, which are much, much larger? By splitting their image file into many smaller "sparse" image files, each of which is below the size limit. There's probably a tool for doing this, but I don't know any details.

TWRP, or another custom recovery. They allow you to create and restore backups. TWRP has some automation support via OpenRecoveryScript.

So, if you have 700 tablets to configure, you can configure just one, then save its state via SPFT or TWRP, then restore that on each other tablet.

What is its "state"? Well, the system, cache, and data partitions. The system partition is normally read-only and won't change, therefore you do not need to clone it. Unless you install root and modify stuff on the system partition, of course. The cache partition is quite irrelevant. It is the data partition that has all the app settings.

However, if you clone the data partition from one tablet to others, then you're causing each tablet to use the same Android ID (a long number identifying an Android device, usually randomly generated when Android is first booted after a factory reset), the same Bluetooth and WiFi MAC addresses, and some other IDs that should be unique on each device (the tablet's Lenovo serial number might be in some cloned files as well, e.g. the WiFi settings).

You can at least avoid cloning the MAC addresses by deleting the entire directory /data/nvram/ before you create your backup. MediaTek devices have a dedicated NVRAM partition that contains the MAC addresses and some other stuff, and this data gets unpacked to /data/nvram/ when Android boots. Unless the files there already exist. So, by deleting /data/nvram/ before you clone, you force each tablet to extract its unique MAC addresses again at the next boot...