Ive not had the motivation to work on this for a while. While the data does appear to be decrypted, it includes "handshakes" which im not sure of the proper method to generate those. I never tested sending custom data from an external device as of now. I was at the time considering writing homebrew for the gbc's ir port (i think i did the math back then, i believe it should be fast enough). I think i have even written a gbc rom for reading the signal, although i might have lost it when i got my new laptop and the hard drive i used to transfer my files failed midway (dont remember if it was a survivor). IR transmitting is pretty cheap though for arduino and stuff. I never tested the rom i wrote on physical hardware (gbc flashcart is a nightmare with lack of drivers. Also didnt take the time to repack the rom in gsc vc since apparently that uses the 3ds ir)
Last edit: if i come across the gbc rom, i think it should be fine to share here since it is homebrew (maybe a mod could clarify that). Thats in the case i find it though
like a 250 dollar kit back when DDR4 was Intel only