Here are his biggest conclusions:
Conclusion #1: Dual rank DIMMs (yellow) offered the best performance amongst “set and forget” (light blue, orange, yellow) memory configured automatically by XMP profiles.
Conclusion #1a: But the increased overclocking headroom of single rank modules was more than enough to overpower the benefits of rank interleaving, so manually-tuned single rank DDR4-3200 and 3466 won the day (dark blue and green).
Conclusion #2: BankGroupSwap should likely be disabled for users that want the best PC gaming performance. As always, test your specific use case. Conclusion #3: Chasing the highest possible clockspeed required timings so relaxed that real world performance suffered versus lower frequencies with tighter timings. This is a fine balance, however, so testing on your platform is always helpful.
Conclusion #4: Geardown Mode should likely be disabled if your overclock is stable with a 1T command rate. As always, test your specific use case.