My findings for noobs like me, based on my sticks (2x8Gb) used on 2 boards after faffing about with these last few weeks:
Dont bother with anything other than primaries and tRC + tRFC, you will only get micro gains, if any at all and sometimes worse and usually end up spending hours trying to nail down which one is giving you errors. Yea memtest will run a bit faster but so what if you getting errors.
Let your motherboard sort out all your CAD BUS, Proc ODT and Rtt settings (unless you can't post at all), yea the Dram calculator settings will get you booting cl14 mega speeds etc if you change all these but you probably going to have errors unless you got amazing sticks anyway.
Any tRFC under 600 will eventually give errors at any high speed 3600+ (not tried lower speeds), tRRDS set to 1 will give errors always, use 3.
Power Down Mode OFF
If you get a hang, no post then bios reset after changing a lot of settings, don't give up, reload old settings then change again and see if it works. This happens sometimes even when changing to known good settings when certain settings are changed.
When overclocking infinity fabric for 3733+ use 1.05v VDDG, it will pass memtest fine at lower voltage but when you try to play a game audio will be screwed up, this is common. 1.05v is actually the default but I use less for 3600 and Dram calculator recommends even less than that. This probably down to the CPU I guess?, I have a R5 3600, some better CPU's might have better IF that runs at lower volts.
Check actual voltage using HWinfo as some baords over volt ram, in my case by 0.024-0.036 so I use 1.38v for 1.4v. Ryzen master will only show you what you input not actual.
Settings that absolutely work for me, 10+ memtest plus hours gaming.
3600 16-19(19 tRCDRD + 16 tRCDWR)-16-36-62-620, Soc 1.1, VDDP 0.9v, VDDG 1.0v, 1.40v Dram, Spread spectrum off.
3733 16-19(19 tRCDRD + 16 tRCDWR)-16-36-62-620, Soc 1.1, VDDP 0.9v, VDDG 1.05v, 1.42v Dram, Spread spectrum off.
I imagine these Dram Voltages can be tweaked down a bit too.
Ive benched the 3600 profile against the Safe 3600 Dram calculator profile (that has much tighter secondaries downwards), there's no difference in bandwidth or latency.
My 3733 vs the 3733 Fast Dram calculator settings is fractionally lower bandwidth and same latency but the Dram Calculator settings will give errors for me.
I'm just a noob with Ryzen builds but hope this helps some save a lot of hassle chasing holy grail settings that are not worth it.