[Q] MTK (Mediatek) Repartitioning 101 gone wrong

Hello guys, for the previous year I would say, I have read about repartitioning MTK phones, starting with my old Cubot MTK6572 (Rest In Peace) to my current Doogee MTK6582.

I have tried countless times to repartition using the EBRTweak utility, or changing the EBR1 & EBR2 files myself but it never, ever works.. :( I always manage to get in the first initial boot and have a false victory where I see that I have re partitioned successfully, but after I reboot after, I always get a boot loop after that initial boot.

For editing the EBR files, I have tried:
-Using EBRTweak
-Editing myself by changing the values from scratch by making calculations with sectors, bytes and addresses
-Editing myself by
First adding a value in the /data partition length, adding that value
Second adding that same value to the start address of the FAT partition
Third removing that same value to the length of the FAT partition

For flashing the EBR files, I have tried:
-Flashing all the patitions with SP flash tools with the new EBR files (without changing the Scatter file)
-Flashing all the patitions with SP flash tools with the new EBR files (changing the Scatter file)
-Flashing only the EBR partitionsa on a working ROM
-Flashing the EBR files using an updater-script via a custom recovery

With each of these methods, all my calculations were exact when I verified everything (to the byte), including using "disktype" command in Linux.

So after one year of failure, I finally decided to post on XDA to ask for help... please, please, does anyone know why the first boot works but the second boot always ends up in a boot loop? :silly: