Look, just tie the f'ing EDK and be done with it. It is widely-used, time-tested, and lab-approved for recreational rappeling. It is used thousands of times every year with no incidents. It is approved by the AMGA for guiding purposes.
Or alternatively, use the time-tested double-fish if for some reason you don't believe what reality tells you, that's fine too.
Learn the core set of knots and get really good with them. Don't mess around with a million options. There's no point to it. Just choose and be done with it. You'll live.
I'm sure this topic will come up again.