How to root a BLU M8L tablet?

I've recently ran across a BLU M8L tablet. If there's a way to root this device, I'd really appreciate the info. So far, I've managed to unlock the bootloader through modified fastboot and spreadclient found on GitHub. I'm running a Linux distro on my computer used to unlock the device. I found a patched boot image on XDA and attempted to flash boot_a and boot_b, but this spun the tablet into a boot loop. It is an A/B device so I'm thinking the problem is in vbmeta.img. I've bought a second tablet and unlocked the bootloader on it, but hoping someone has knowledge and could explain how root was achieved. Don't want to brick another.