It doesn't work that way.
TWRP depends heavily on the fstab of the device model in question, which describes the partition layout of the storage. This is not related to the SoC (processor), and almost never the same between different models.
The ROM you provided does not contain a valid scatter file or recovery.img so you can not use SP Flash Tool.
I recommend you to make a backup of boot, copy the boot.emmc.win to PC, then to another phone and patch it with Magisk Manager apk
After successful patching, copy the patched file back to PC
Reboot the phone to bootloader, and flash the ...
I can't see the question here ?
Are you asking what the driver is for ?
Please have a look at this video to understand what the preloader is, MTK Backup & Restore
The Mediatek Preloader is used for flashing new image's to your device.
Their is two different boot loaders on Mediatek device's..
MTK DA USB - For flashing the Preloader
After a backup, I tried to delete the nvram folder (via adb root ; adb shell ; su - ; mv /data/nvram somethingelse). I do confirm that this folder is created from scratch when you reboot the device.
So the answer is yes, it is safe to delete the folder.