I posted some info a while back with charts showing the effect of Memory timings and subtimings - at least on benchmarks. Of course, you want to make sure your RAM is on your motherboard’s QVL list.
I’ve found that just the first High Efficiency Mode preset, “Relax”, helps, and even though “Tightest” passed all the tests I could throw at it, MSFS itself was a little unstable, so I backed it off to the “Relax” setting and have left it there since about September.