Just tested this:
https://www.fruugo.co.uk/nk-s4…p60/p-242559432-522105197 (delivery to Norway 10 days)
with an AppleTV 4K 3rd Gen.
WLED with a 5m 300 RGBW strip behind a 75" TV.
The HDMI cable that came with it did not do HDR, so had to swap that.
Then I was able to select this Video setup on the AppleTV:
Sadly HDR10+ was gone, but I lived without that with the 2nd Gen ApplTV 4K, so I can live with that for now.
Selecting the Video Capture in Hyperion was plug & play and using these settings, lag was down to a few 100ms. (WiFi WLED)
Yes, and CEC was broken, but making a solder bridge for R12 as described in the link below got it working.
Adding CEC support to cheap HDMI grabber with 4K loop through and HDCP 2.2
Works with all streaming services so fully HDCP compliant.
So, summing up, if you can do without HDR10+ (haven't tested Dolby Vision) this is a cheap option to get started.