I made the switch from raster to Vector Tiles for my maps sometime last year and so far I've been really satisfied with my decision. I have been making tiles from zoom 1 to 21 and it's been a real struggle trying to tile large areas till zoom 21.
I realized that since vector tiles contain just the vector data they are essentially the same for higher zoom levels, just of a smaller extent, so I could skip making the tiles and simply reload the previous zoom level's tiles. I tested it out by limiting my max zoom to 17 and viewing the map at zoom 21 (zoom 17 tiles reloaded at zoom 21) and couldn't find a difference in the rendered map (the missing labels can be handled in my renderer).
Can I skip making tiles for zoom 18+ and use the zoom 17 tiles till zoom 21 without any problems?
I am using TileStache to make my vector tiles (for Pakistan only, not globally) and it stops simplifying geometries from zoom 16