A better firmware flasher app + an advanced re-flash app option for bad flashes
You need to prioritize a better firmware flasher app. I lucky didn't brick my HS611 with the T19c_211209 firmware but the firmware app no longer see my tablet. everything still works, but i don't think i will be able to update the firmware anymore with the current app.
Can you make/release an advanced re-flasher app for bad flashes. From my research GD32 has an official DFU tool for flashing there MCUs.