Check out my hypers. ? /s
2100 6-7-5-20-64 1T PL6 works fine for 1M, ran out of LN2 before trying 32M. RP4 was unstable in 1M, didn't try lower RAS or RFC but probably can be tightened a bit. 1.95V worked fine for me.
Edit: also this was 1M with wazza, so at least some stability needed for that.