Handicap idea is interesting, would it be easier to just have an extra lap for the race and all drive around then line up in race start order aka warmup lap. As long as everyone knows who they should be ahead of and behind it shouldnt be too hard to sort the grid. Not sure how people will get the start time though to set exact time gap for all cars.
One thing with the track is t1 is very prone to abuse and large time gains but I wasnt using it on my laps. All should try and keep 2 wheels on track through the first chicance even though a big 4 wheel jump can cause you to land awkward and hit a wall there is .5 or more to be gained by never intending to take the proper line.
With the handicap I also figure race 1 the guy leading will want to win by the smallest margin possi le and the one in last will want to loose by the largest margin probably.
Maybe have time gaps just for all but the first and last cars to have a fixed 2 second gap to the next car. Maybe even run a reverse grid with 2 seconds to all cars so if there would be 20 people on the winner from the last race would start 40 seconds behind. Using the lap timer would still work even if we had a warmup lap and maybe start the race on the next minute once all are lined up.