I have a crappy kit of Crucial Pro Overclocking 6000 C36 ram, just the cheap stuff from right when the rampocalypse was starting. I attempted a 6200 tune of this kit but most timings just wouldn't really budge much, with or without voltage.
Lo and behold various niches started posting the 4400 thing, so I thought I'd try it. The tune above is completely stable and passes yc vt3, karhu 24h, etc.
Attached is a fh6 benchmark for an example- first screenshot is my tune, second is 6000 defaults with 2000 fclk. I'm pretty surprised at how much of an improvement it was.