6.5 x 6.5 grow tent additional support

This will be my first big grow. I have a 6.5 x 6.5 yieldlab grow tent. It’s made to support 140 lb. but I am wanting to add a 3rd light and just when I hang on the cross braces the tent says down from too much weight. Has anyone ever added 2x4 and added extra support to attach lights?

Some tents (2mx2m or bigger) come with a central pole for that reason, no reason you can slap a 2x4 in there.