If you just need some bike time and you've got a crap set of tyres, go for it.
The tracks are totally unmaintained at Parwan, so it can be a good workout on a rough, rock hard surface. If you practice there every week, it would be great prep for something like Supermoto.
Good on them for keeping it open though, it's a great place for little kids & novice adults to learn. Lots of open space.