Recently I saw an interesting video about chip decapping using only hot air.
It looked quite easy so I gave it a try and indeed I managed to extract three dies without breaking them or any other problems so it was 100% successful on first try.
You can see die pictures below. From left to right: GD32F103C8T6 main die, it’s flash and MAX7219
For comparison, you can see professionally decapped GD32 by zeptobars here.
Next time I plan to use some chemical method to uncover the flash without damaging the chip and try to probe the signals while running.