I only used just over 1,300 objects out of 2,100 available, so plenty more could be added if required by anyone who wants to use the layout.
I originally had route markers, invisible marshalls and some slabs laid near edge of ramp wall, to act as a sort of pavement/sidewalk kerb, but I eventually removed all these to give bit more freedom to drivers to risk taking shortcuts over some of the bumps/corners.
There is risk taking too much of these corners as it can throw you off course, or cause you to spin, or go over edge, etc.
If you do go over the edge into the middle bits, I constructed some circular walls to play around in, as a sort of consolation for being out of a race.
Another reason for not putting too much more in, especially coloured objects, was that I wanted it to be difficult when racing someone, for the drivers to have difficulties in differentiating track surface from sloping walls. If they stuggle to make out route when racing someone, then there is a chance for the more visually acute to make up for eyesight what they may lack in driving skill.
Because there's a lot of grey on grey, it's very easy too miss something that might be in front of you when going at speed. If you look at video at about the 1:30 mark (near end), or if you race round the circuit, you'll find that the overhead concrete gantry that holds the lights is almost invisible. Some other objects elsewhere round the track are the same.
If anyone does decide to use this layout on their server, I'd love to see a replay to see what kind of mayhem might be involved in a race.