I would have a form, if your team is entering & in the top 25, you fill out the form. It would show your 9 set members (5 main, 4 subs). Once you turn in the form, you can't change members, can't fool around switching 10 minutes before.
-Why 4 subs? 98% of graalians still live with their legal gaurdians (parents, grandparents, relatives, etc), they are kids. Things happen, parents decided to do things, and much of the time, the kids don't have a choice. So this would allow a solid fight between 5 on 5.
I would have it as a private room, to reduce lag & distractions. A staff member would livestream it, so people could still watch.
I would have a bigger room, much bigger. So it is based on skillz, and not on ripper spam in a 45x45 level. Traps? Hell no, this is based on skillz, not luck and other obsticles.
Those would be some things I would do, what would you do?