Perfect Total Backup of your Firmware

The safe way to do this with or without a proper scatter file is the "Read back" feature of SP Flash Tool. There are MANY reasons to dislike MediaTek, but this feature is so nice that I can forgive them for most of their wrong doing.

Most of this section I will generalize from my Lenovo A2107A Guide.

Here is a cookbook for doing a total backup of your MTK device with MediaTek's SP Flash Tool. No rooting, you might even do this before you ever boot! I have basically done this with both of my devices before I fiddled too much. I recommend doing it before you do anything really.

1. Install VCOM Drivers.
2. Install SP Flash Tool.
3. Grab an SPFT ROM, really anything should work, you just have to make SP Flash Tool happy. SPFT validates the scatter file against some of the image files, so you have to calm SPFT down by giving it something it can make sense of. We won't use the scatter file or image files while we do the "Read back" operation.
4. Run SP Flash Tool, Open Scatter File
5. Don't play with anything, go into the "Read back" tab (This will read your flash to a file on your PC)
6. Click on any items in the list, then click the "Remove" button
7. Now click the "Add" button
8. Double click on the "N/A" under Read Flag
9. Type a file name to write to, like "WHOLE_ROM"
10. Now it will popup a window "Readback block start address"
11. Leave "Hex" selected, Start Address" 0x0000, Length: 0x40000000, Click OK (NOTE: this will get the first GIG of flash)
12. Click the "Read back" button
13. SPFT now waits for you to connect your device and put it in Meta Mode
14. Without plugging your phone/tablet in, tap the Reset Button or make sure it's fully off
15. Hold VolUp, plug in USB, Release VolUp (putting it in Meta Mode) <--- Important
16. You will see the progress bar moving. Total backup takes forever, because in this mode SPFT seems to not do USB HIGHSPEED
That's IT! It'll take a few hours, so go to bed.

If you ever restore, just go into Recovery and Wipe Data and Cache. (as these are large and we probably didn't back them up above)

Note: "Length" in Step 11 is probably long enough for most devices. You can reference the scatter file you made above to make sure get everything, but you don't need USRDATA or CACHE, as those get wiped anyway.