I've only participated in an couple of Vinduro event and only one of those was timed.
My experience is that they are bloody brilliant bang for your buck .. the best in the Vintage scene. A more relaxed atmosphere than VMX and that's not saying VMX is bad, it's not, but just that the Vinduro scene is easier going in my humble opinion.
In those 2 rides, I've not had an issue with a) being passed, or b) passing someone else and to be honest, with the good comradery that I have been lucky enough to experience so far, I'm surprised it's an issue for anyone. If I hear someone coming behind that is obviously faster then I will take all steps necessary to safely let them by. Easy. If I happen to be approaching someone else then I will take all steps necessary to safely get by. Again, simple stuff
If a faster rider happens to short cut a corner to pass a slower rider then I would not have an issue with that because the alternative is likely to be a frustrated block pass where the faster rider jams it up the inside of the slower rider and that's not what we want is it?
Anyway I just wish we had more of them up this way. Our VMX scene is strong and it would be great to have a Vinduro scene that equalled that.