KLEVV is from Hong Kongnese Essencore.
Team has obviously been around quite a while, hardly an up and comer.
OLOy I wouldn't touch with a barge pole.
Lots of odd brands here like Orca, Leven, v-color, anacomda (yes), AGI, Utwin and even Pioneer these days.
Apacer is apparently back in the DRAM business and somehow Geil is still in business. Lexar, the brand Micron sold to some PRC company is also doing RAM now.
Your last point makes sense, as I'm sure it's the kind of thing Micron would do if they could earn more money on it than selling their own sticks of light up RAM.
There's your problem, Nanya chips.
I have their 3600MHz modules with Hynix-CJR and they both run at higher clocks and tighter timings, plus I'm using four sticks.
The big problem with all the fancy heatsinked memory modules is that you are buying the pig in the bag, as you often can't tell what DRAM chips you get. When memory makers then have multiple revisions of the same modules, without letting their customers know, you can end up with all kinds of random stuff.
Did you try contacting Patriot? Their support is actually quite good. I bought one of their NVMe SSDs and the thermal pad didn't touch the controller, so it was overheating to the extent it made my system crash, even though it wasn't the OS drive. They swapped it out, no questions asked.
Got several mates that have bought higher-end Viper Steel modules than mine and everyone's happy with their RAM.
Everything over 4000MHz should be Samsung B-dies.