Cutting out doors in plywood panels

I'm working on my galley setup and I would like to cutout my openings in the plywood and use the plywood from the cut for the doors. Not sure that is the best explanation, but a bunch of commercial trailers have their galley and inside cabinets done this way (Wibtech, Timberleaf, etc). I'm guessing that these are done via CNC, but I would like to do this with a router in the garage and thinking about how to do this.
My thought is that I could make a jig that is the size of the opening. Then drill a starting point with a 1/4 inch drill at the edge of the jig, probably where a hinge would be in case I need to hide the starting point. Then use a pilot panel bit to route out the panel by running it up against the jig that is attached below the panel, sort of like you do when making an opening for a window or door when framing an exterior wall. I'm planning on using 1/2 inch Baltic Birch.
Or would I be better to use the jig on the front as a template and use a top bearing flush trim bit and just make a bunch of passes.
If things go really sideways I could just cutout the doors separately, but I would like to eliminate as much waste as possible.
I'm hoping my description makes sense.
If there is a better way please let me know. I've only ever used a router for cleaning up edges and cutting some dados, nothing like this.
My thought is that I could make a jig that is the size of the opening. Then drill a starting point with a 1/4 inch drill at the edge of the jig, probably where a hinge would be in case I need to hide the starting point. Then use a pilot panel bit to route out the panel by running it up against the jig that is attached below the panel, sort of like you do when making an opening for a window or door when framing an exterior wall. I'm planning on using 1/2 inch Baltic Birch.
Or would I be better to use the jig on the front as a template and use a top bearing flush trim bit and just make a bunch of passes.
If things go really sideways I could just cutout the doors separately, but I would like to eliminate as much waste as possible.
I'm hoping my description makes sense.
If there is a better way please let me know. I've only ever used a router for cleaning up edges and cutting some dados, nothing like this.