I wax up about every 5-6 days for each pair. Im mostly skiing Colorado in places like Steamboat, in Utah, and usually a week at Jackson. The runs I ski are all about traverses and runouts, so speed really helps. Even at the local Boulder hill some cattracks between lifts need speed. Edges I only do when I cant hold whatever we get in the Rockies that qualifies as ice, which is not much. So once or twice a year per pair for edges.
I think I believe somewhere in the back of my head that skiing dry bases fucks them up. Whether thats true or not probably doesnt matter much. Quick drip wax inside on the workbench, then a scrape a rotobrush outside when cooled. Take very little time, makes big impact. I just use universal wax. 90% of the benefit, 20% of the work.