It is amazing the controller you developed. I am making the opposite, to use an Esp32 microcontroller to communicate to the bluemind controller and also control some new warning system and later to control the angle of the motor into the water. I probably burn my nRF5280 
I am trying like hell to extract and understand the protocol of the controller nRF52840. I had already extract the binary code and also convert to some C low code structure, hex, using a dissemble program (radare2) and raspberry 4 ports and OS. I could share the code with you, but tou probably already have it . 
I am not getting how to communicate to the controller. It’s look like to be Bluetooth in 2.4GHz but I am not finding it. Maybe the is some hiding function and password .
could you also share with me your communication code? 
And maybe some info about how to communicate to the original controller. I am desperate and my wife is already blaming me and my board, because I am spending to much time trying to fix this problem and that I should spend more time doing something else
HEEEELP
and nobody on alibaba can forward me your contact.