In theory you could go larger to cut a single-piece circle. I don’t know how to get it perfect, but (again) in theory, you could start with roughly circular material and stick the edge into the passthrough and cut some sort of partial arc.
In this setup, for example, it’s a 36" diameter theoretical circle.
Of course, I have no idea how you’d align that to be “perfect”, so it’s probably a nonstarter.
You could make a multi-part circular frame to use as a router template, thus enabling virtually limitless size. Make the arcs interlock and form a larger circle, and then run your router on it.
In fact, that’s probably how I’d tackle it if I were doing it. Like so, here’s a 12-part 36" interior diameter or so circular ring, ready to assemble.
That can be cut in one job, it’s 1" wide and fits nicely in the bed.
Of course, I didn’t kerf adjust this (and subsequently flip half of them to make a better fit), which I’d feel compelled to do because that’s how I am, but this is the general idea.
Sometimes the laser is a metatool for your larger goal. I’m willing to bet that the router solution will be nicer faster than trying to align a ton of cuts in the passthrough.