I'd be concerned for the bucket using bucket forks with a load like that?!
I've been wondering about stacking with them cut - so far, I've left the top ring uncut, which results in regular head-bonks... but I've been wondering if - when full of wood, it's not like there's much outward pressure on the cage; it's not like it's a water tank... the vast majority of force goes directly down onto the floor of the tote, unless you're stacked. And, if it's stacked with the upper tote actually being on the lower cage, is it really going to be bad to have a gap? Would tossing a couple 2x4's or even 4x4's to act as a header be better?
I'd kinda like to get rid of the top of my tote "doorways" but I do stack a few totes in my barn during the winter.
Also: when I cut the tote cages for the "doorways" I cut at about a 45° angle and briefly clean up the edges with the abrasive to reduce chance of encountering sharpness...