There are ways to increase the data transmission rate of TxQR by using color.
Currently both JABCode and HiQ have released sources for such items, and OpenCV is considering to add them to their repo.
JABCode: https://github.com/jabcode/jabcode
HiQ: https://github.com/ouyangzhibo/HiQ-Robust-and-Fast-Decoding-of-High-Capacity-Color-QR-Codes