Jonathan,
Our solution is to cut the post feet to length on site after we shoot the elevations of each post location and any benchmark or existing/adjacent structure we're working to/from and calculate each one's variation from a theoretical zero.
The survey takes one guy just a few minutes now that we have a rotating laser.
Sometimes if the site is close and the deck/slab is ready, I'll go out a few days before we finish cutting the frame and layout for the posts and shoot the elevations and bring the info back to the shop where we then layout and cut the post feet and do any prep for the connection to the floor/foundation.
