I had actually just finished reading through these tutorials as it was recommended to me somewhere else. I actually do have these items laying around, so I think I'll see if I can look into following the tutorial but I'll definitely reach out if it stumps me!

When practicing speedruns on emu before console (PS2 specifically), I've used OJD. What hardware/software would one need to capture console inputs for stream similarly to OJD? I've seen MUNIA online, but it appears to be sold out. Looking mostly for mostly my PS2, but will also need something for the GameCube in the future. Any help or suggestions would be very appreciated!

Would probably continue to be disallowed as it still is an unfair advantage. It would certainly help me too though, as my edema in my arm gets really bad having to reset and mash those first 6 minutes over and over again.

You should join the Digimon Speedrunning Discord! The World 3 channel can answer your questions better there.