I'm curious what the community's take on this is? I'm more interested in the Home Networking side of things but I'm not sure there is enough of a critical mass to have dedicated communities for both enterprise and home yet. Is it better to start together and then split as it grows?

Generally speaking they look good for the ideal situation. However, it is far more common to not be able to isolate the cable modem from the MoCA network. For it to work as pictured you need two coax runs to the location of the cable modem and router. Most homes only have one run to each room. You could place the cable modem near the utility closet but that is usually a pretty bad location for an access point. Most MoCA installed end up with a single coax network and the point of entry filter on the far left.

With regards to the point of entry filter in the second diagram: as noted in the image you do not the filter since the MoCA and CatTV network are completely isolated.

Can you test without the MikroTik? I've been having similar issues with my Mikrotik set up (I had a half a dozen or so posts on reddit about it). It appears the devices are not handling flow control correctly and the buffers are being overwhelmed. I'd test first without the Mikrotik and then experiment with flow control on the port. Be aware that you seem to have to disable and reenable the interface for flow control to take effect (or reboot). It has been getting better with more recent versions of RouterOS but it is still not "right" it used to be much much slower.

Edit: fixed a typo