I don't really know much about building anything so I was trying to keep this as simple as possible (2x4s and OSB, wood glue and screws). I'm worried about the highlighted legs bowing.
This is for a grow box I wanted to build. The top part is a hood, and the front will be a hinged door. I'm trying to avoid another horizontal support across the two highlighted legs because I want to be able to have a completely open space from the front and top.
The hood would have an additional 10lb load from hanging lights. The inner table will hold a tote with up to 8 gallons of water.
Best Answer
The legs will not bow at all, all the force acting on it is pushing straight down. There is nothing going on the inside to act upon it to push out, so this will hold anything you wish to place in it. It will also hold an incredible amount of weight on top without no bowing of the legs either, if you added an apron that is attached to the top the same way you have a front stretcher at the bottom. If you did the top a little differently and made it so the top blocks "keyed in, or just added a few removable screws, it would help hold the front together.That way you could still remove it when you need. Like this without the screws at the top, it will not bow, maybe spread a little if you don't fasten the top.
I added your modified picture to help show what would help