Enabling calo cells causes a big performance hit

[EdwardMoyse]

On my M1Pro mac, I can enable all event data except CaloCells in the ATLAS example: https://hepsoftwarefoundation.org/phoenix/#/atlas and I get 60 FPS. But as soon as I enable CaloCells this drops to 9FPS. This seems quite surprising so I wonder if there is a performance bug here.