Yeah AWS is the league which oversees battles with the Ants
I built an arena which is housed at the Swindon Makerspace, and it is a polycarbonate lid with sides that fits onto the wooden arena. It was made for AWS specs as the cost of the material, i decided it be a shame if it couldn’t be used for an AWS in the end.

Maybe a sketch to show your idea and suggestions can be made as to design.

With the curved polycarbonate, if it is big enough, then you can get the flex from a sheet, there is a curved battle box in the AWS leagues... will find a pic