Just make oval pistons, then it’s technically a V4, even if it has two spark plugs, two sets of 4 valves, and 2 connecting rods per cylinder.
That’s the approach Honda used on the NR500 racer, to try to get a 4-stroke to be competitive with 2-strokes:
It, however, wasn’t very successful.
A later 750 cc version was then designed for endurance racing, and then made it to the road as the NR, with 300 sold - that parts diagram at the top? That’s from the production engine.