I think you're being a bit harsh.
I was a little surprised that SYO were having a forest event at this time of year. I guess it was mainly for the school's champs so the TD5 courses were just an add-on. Obviously the vegetation is going to be an issue and I thought the Planner did the best they could given this. I know they also spent quite a lot of time cutting routes through grot to minimise unfairness for early starters.
I think you have to accept courses like this at this time of year or just stick to urban races.