Faster RAM for 2020 iMac (27")?

[miretogo]

Apple lists the frequency as 2666 Mhz and does not mention CAS latency:

Install memory in an iMac - Apple Support

Get memory specifications and learn how to install memory in iMac computers.

support.apple.com

Has anybody tried faster RAM? Does it work? If so, at what frequency?
Does the CAS latency of the RAM make a difference in the iMac (for macOS and Windows)?

My guess would be that Apple's firemware clocks faster RAM down anyway but it would be great if somebody could verify/falsify that assumption.

 

[miretogo]

I just saw that the following thread discusses the same topic and already has numerous posts:

Memory upgrade compatibility list for iMac 2019-2020

Since many people were asking which RAM modules they could use to upgrade the 2019 or 2020 iMac, here are once and for all the compatible memory modules for both models. Feel free to add any kits you personally tested. Memory upgrade compatibility list for iMac 2019-2020 Compatible Crucial...

forums.macrumors.com