For testing, I’m looking for sinks and adapters using the MCDP2900 chip. I learned from this forum that CAC-2504 is one of them. Do you know others?
StarTech.com usually lists the chip used in their adapters. Google it like this:
MCDP2900 site:startech.com
You can do the same for club-3d.com.
MCDP2900 site:club-3d.com
They don’t list the chip in their product info pages, but they have this forum which has some posts containing the info as you’ve found. See this one for example:
https://insights.club-3d.com/thread/usb-3-1-type-c-to-hdmi-2-0-uhd-active-adapter-hdr-support/
You can do the search for stores like amazon:
MCDP2900 site:amazon.com
You may find more results by doing the search using the store’s search option instead of google.