We ran vertical piston ports on our 4-stroke race karts for a long time, then switched to lateral piston ports because of carbon problems. It's not snake oil. Our lateral port motor burned a LOT less oil (remember, 4-stroke) than before it was modified. It also had less blowby and leaked leaked less compression at the head (that might've been something else, but whatev). It also allowed us to run quite a lot more lean; like, a half turn down on our Tillotson adjustables. These are 30+ hp Honda GX200 motors.
Lateral piston ports are so easy, you might as well just make the modification.