Printed in Jesse PETG with a 0.8 Nozzle and in Matterhackers Tough PLA with a 0.6 Nozzle with prusaslicer default structural settings and it's holding up fine with two brackets holding up 5' of conduit full of filament. Added teeth to interface with 6 holes instead of four just to make myself feel better. 
 

Update:
Turns out the v3 design didn't work as well with PLA as it did with PETG. When the part was rocked into place I think it put too much stress on the top tooth causing a crack to formed that failed over a period of time causing the shelf to tumble. I have gone through a few designs and found one that seems to be holding better when printing in PLA and have included it as v7. 

The PETG prints are still holding up without issue since first installing the shelves.