After building my own control panel, I have to ask, why all the plugs and recepticles? Seems like everyone loves carving out square holes in their electrical boxes for outlets to plug into. What a PITA. Why not knock out a standard hole and use strain reliefs and just hard wire your cords in the box? Yes. You'll have cords coming from the box, but man so much less work and your box will retain more of it's watertightness.
This isn't a reflection on your build, just something I've been meaning to ask as I see almost every build done this way and it doesn't make sense to me. All it does is cost more money with more parts needed, take more time fabricating, create another opportunity to make the panel look shabby with jagged holes depending on the skill level, cause unnecessary wiring terminations and therefore more failure points, decrease interior panel space, and create more opportunities for water/debris to enter the panel. All just so you can have cords to roll up and put somewhere else?
