Looking into upgrading my toaster's RAM from 8GB to at least 16GB, and I'm stuck looking up speed and CAS latency.
I figure the higher the speed and the lower the CAS the better, but I'm not sure what the exact limiting factor is nor what difference 9001MHz, 2 CAS RAM makes over a 8999MHz, 1 CAS.

Looking into the mobo (PRIME B350M-A) QVLs I see speeds ranging from 2133MHz to 4133MHz, then looking into the CPU (Ryzen 5 1600) I see people mention it's rated for 2666MHz, but also "muh overclocking" for higher speeds and just getting into researching that topic is sucking all the will out of me.

Picrel for more detail.
Other details: 243V5LSB/00 monitor (1920x1080, 60Hz), MSI GTX 1050 Ti X graphics card

So, what am I supposed to do here, is 2666MHz a safe choice?
Am I supposed to push for more, lean into overclocking?
What even are some sane CAS, how do I know when to compromise for more or less CAS over more or less speed?

Also, any reliable names or names to run away from really fast? Looking through my options I barely recognize some of these, and most of them are just a single 5 star rating which doesn't inspire much confidence it's not just shilling

Maybe I'm just overthinking it and should go into whatever. Or maybe I should go for a whole new PC, but this one's been serving me quite well other than running out of RAM a bit too often