Well, when the fiber is installed they are going to be installing a box for the fiber to run into, then will be installing an ethernet connection inside of your house. That is just part of the standard installation for fiber. So I guess I’m just not understanding why you are trying to force the connection into coax.
If you are trying to avoid having a line run into your house you will need to talk with the installer to figure out what your options are.


Then you should definitely talk to the installer prior to signing up. That is definitely not a standard install, and I’m not sure they would have any way to weather proof an install like that.
I don’t have an answer for whether your MoCA plan will work since that isn’t hardware I’ve worked with. Sorry I can’t be more help.