As stated in the post you referred to, technically Rockchip devices cannot be bricked.
Since you flashed a wrong image, it probably not right to say internal flash doesn't contain bootable system. Rather that system is wrong and cannot compete boot hanging somewhere, eg ddr init.
So I guess you have to go by the mask room path to recover (flash correct image or erase internal flash to enable SD card boot, which might be easier to experiment with).
el es reacted to MaxT in When can an embedded device be truly bricked?