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).
This is the original zoom 21( with zoom 21 tiles):
And this is the zoom 21 with zoom 17 tiles reloaded:
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
node-mapnik
can be used for this. These can still be cached, but you won't need to create them all before you can start rendering them. Globally, zoom 19 has more than 270 billion tiles.