In response to Q1, if it didn’t come on the chassis out of the box, it’s not allowed. The carbon fiber and full metal chassis have a set of parts that are standard. Those are what’s allowed.
In response to Q2, Mark, I tested all tires that were available to us included the Paul Gage tires. They didn’t perform as well as the MJK thus they were removed from contention.
All tires appear to be in Austrailia so allow for 2 weeks shipping. Tires can also be sourced from this eBay seller: https://www.ebay.com/itm/ScaleAuto-1-24-Sports-GT-Race-tyres-MJK-4118/392035360419?hash=item5b4720dea3:g:5fIAAOSwL2NakLto
I have already purchased 5 pair from him and all but 2 pair have arrived as of the writing of this post. I’ve also got tires coming from Armchair and got an email yesterday that MJK is making the tires this week and Armchair will be shipping to me next week. I had ordered 5 pair and 4 pair are already spoken and paid for.
As the series manager, I’ve tried to make the series as even as possible and getting the resources necessary for racers prior to the race.