FYI here is my network cabinet as of this afternoon and just getting fiber

Excuse the 3 cables out the bottom, i havent installed my network rack and patch panel yet, going in a separate cupboard, and thats where the other 2 blue un terminated cat6a cables go.

There is a bit of space in there but to fit an ONT, Router, Switch and patch panel you need to be careful about placement of things.

Thats how far the ONT sticks out:

Here is how big the ONT power supply is, you would struggle to mount this on anything except a vertical power socket, the other problem is most Router power supplies are the same shape so you could plug 2 things into a double vertical socket. i will be putting in a constant vigil sentry UPS soon which will allow me to only use one power socket in there and remove the multi board.