Racing AI

So I looked into getting the AI to be faster.
I stumpled upon Gull's Asphalt Race Scenarios. In the first versions he used a flowgraph where one could change the AI Aggression in the race json files depending on the waypoint. In the most recent version he just created scenarios and just used the race json as is. So i figured that it was officially implemented since Gamergull became also an official member of the team.

In some official files of Beamng, one can also find some this parameter.
For example this:

{
"customFields":{
"values":{
"aiAggression":0.8000000119
},
"names":[
"aiAggression"
],
"tags":{},
"types":{
"aiAggression":"number"
}
},
"mode":"manual",
"name":"Pathnode 23",
"navRadiusScale":1,
"normal":[
0.9974023881,
-0.07168649431,
-0.007037234502
],
.....


But when I tried to play with my own race it didn't really worked.
Is it still officially implemented, so that you can change the Ai aggression depending on the waypoint?
If it is, is there something in another file like the info json file where I need to change stuff? Haven't found anything there.
Or is it a bug, that it doesn't work?