Arena Size Question

[Ocracoke]

That sounds fine for a non spinner arena. The BW champs arena was roughly that area, about 1m high 6mm polycarb walls and roof with 4mm steel floor plates I seem to recall.

[LLL003]

That sounds fine for a non spinner arena.

We're planning on allowing spinners, but at a much reduced maximum speed than in the normal rules (20% robot mass, 200 rpm, 300mm dia) which by my maths at least shouldn't be able to throw a 1KG robot more than 0.5m.
We considered that to be a safe compromise, is there something I've missed?