I just bought a new set of DDR4 Patriot 4400MHz C19 (2x8Gb), which is Samsung B-Die I guess ?

I enabled XMP on my first boot and it's working fine at 4266MHz, but I want to synchronize MCLK, FCLK and UCLK at 1900 (which is the max I can do with a Ryzen 7 5800XT from what I've seen on other posts).

But the issue is, there is no certified profile at 1900MHz, so I can't run this set at 3800MHz (it doesn't even post at 1900 FCLK.

If I try to boot at 3800Mhz memory clock and 1800FCLK it's boots on windows but probably not stable.

I also tried to boot at 1933 synchronized clocks and it boots but I haven't tried to run a stress test.

My question is, what should I do ? Is there a way to still run it at 1900 FCLK ? Should I try to stabilize it at 1933 ? Or should I desynchronize FCLK and MCLK ?

Here is the Reddit post mentioned

https://www.reddit.com/r/buildapcsales/s/d4MAlYIQCc

EDIT:

I tried 2000MHz FCLK synchronized and ran AIDA64 stress test for 5 minutes and no issues. Should I keep my freq at 4000MHz and lower timings if it's stable ?