Hi @Mark Khevin Rogacion, what worked for me multiple times from complete soft bricked state (once I did rkdeveloptool ef and the other time was when I wrote a legacy image to my NAND) was with AndroidTool 2.51 and a copy of the original firmware. Key is the workable firmware and watch out for whether it is NAND or eMMC.
As long as you can get the device to be USB recognized you should be fine. In some cases you would need to press the reset switch inside the AV port, but in a worst case scenario you would need to short the NAND or eMMC pin. I found a picture on which chip and pins to short on forum.freaktab.com. From my attempts, I could not get the firmware to install via rkdeveloptool once I destroyed the bootloader, it showed completed but did not boot.
Hi @jock, @fabiobassa, @knaerzche, just wanted to say a very very big thank you for your work. This has certainly kept me sane and entertained during these crazy times, as well as busy.
If you want me to try anything, I have 2 x Scishion V88 4K RK3229 (MX4VR-01) devices with NAND and I am okay to go experiment with losing my bootloader :-)