So, a little experimenting...
Steup... HWS connected cat6 to router, H2K and 3 joeys on RG6 (duonode/moca), NO HIC.
Laptop connects to HWS via cat6 and HWS provides internet access to laptop connected via cat6/lan.
Laptop connects to H2K via cat6 and H2K provides internet access to laptop connect via cat6/lan via moca to HWS to router.
Laptop connects to Joeys via cat6 but Joeys do not provide internet access to laptop.
Speed via H2K moca was not full direct router speed (150) but did show 80+ with several samples at speedtest, which is as fast as the wireless on 5g freq.
If I had a device without a 5g wan (older laptop, streaming disc player, etc) and wanting faster connection, I would not hestitate to connect it to the H2k moca, which is far end house relative to router.
Darn, I wish I could get the Joeys to provide lan internet access via moca, because I have devices in the Joey rooms that could use the speed of the lan over moca.