Caps are used for emphasis of specific words. I've never heard of anybody who thought using caps was "abrasive" unless somebody was using aggressive language AND using ALL caps. Then, yeah, probably.
In any case, the QVL/memory compatibility list that is available through the product page of every motherboard model gives you a very SMALL sampling of what is compatible, as the board manufacturers only do minimal testing, and only early on.
The memory manufacturers on the other hand do extensive testing because they are in the business of selling memory, unlike the board manufacturers, so they test ALL of their kits on each specific board configuration to ensure there is a clear picture when it comes to their kit models and specific boards. They don't generally revisit it after the initial testing phase though so often kits they release later on are neither tested nor validated, so those are essentially roll the dice kits in the end.
PCPP though, does none of that. They simply check that if it's a DDR4 board, you have DDR4 memory chosen and that if the board supports only up to 3600mhz, that you didn't pick out a 3800mhz kit. So only very basic "this kind of memory can work on this motherboard" checking but no actual validation or compatibility checks of any kind are done by PCPP.
Also, as I always tell people, even being on the list is not always a 100% guarantee because as you yourself noticed, the version of the memory kit might mean there has been a complete redesign of that kit, completely changing it's compatibility with various boards. Sometimes even if it's the same part number, as seen here where three different memory configurations all share the exact same kit model number.
https://forums.tomshardware.com/threads/amd-ram-compatibility.3210050/#post-19785792