Pole Mounted Shelf Bracket - Please Help Optimize

Hi everyone, I am quite a beginner at creating STL files for 3D printing and need help with this. 

This Pole Mounted Shelf Bracket is supposed to be an 8cm column with two 8cm arms pointing out at around 30 degrees for me to then place a 6mm MDF board on top with dimensions 10cm x 50cm. Expect weight of just 1kg - 1.5kg to be place on top of ther board.

I need someone to help me finish up this design as it's obviously not optimized for 3D printing, neither is it print-cost-efficient or load-bearing at all. I barely managed to make this one using Claude AI. I need someone to help me with the design and add some threaded holes for screws when I get the MDF board to fix on top.

Usage: It's supposed to go on the pole of my monitor mount to so I can put my powerstrip and junk on it & sort out this horrendous cable management situation. 

Please help me out

Thanks!
-Abdo