Great work mate, Its quite a relief and hopping for better development support for our F3 from other developers as we now have official twrp.
I have the same problem. I used Arrow v11 and I wanted to change Evolution. I install fastboot TWRP , full wipe install Evolution and my device did unmap super devices. I did mont internal storage and full wipe. Now I have internal store and TWRP recovery on fastboot, but very slowly copied to the internal storage. Copying Evoluton 1.6 GB to internal storage would take 30 hours. Do you know anyone fix or back on Arrow v11 via fastboot?