Baby Step #1: Installation of 150' 600V underground cable

The first baby step in what will be a long summer of a DIY hybrid off-grid/grid-tie installation is coming up soon: A 150' run of cable for each of four 12-panel strings, to be ground-mounted out in a clearing in my woods. I'm using a hefty 9-conductor cable of 10 AWG THHN wires rated for direct burial and wet/dry installation. It won't be direct buried, though. Rather, I'll be pulling it through 1 1/4" IMC conduit because I don't want to have to go down the full 24" depth that would be required. (Call me crazy, but I want to avoid as much as possible hitting the roots of some fairly big trees near the house end of the run.) NEC allows just 6" of depth from grade to the top of the conduit with IMC underneath this little piece of the property, where no vehicles ever go.

The conduit is pretty big, but not much bigger than required by NEC to accommodate the 0.76 inch outside diameter of the cable. I'm using the conduit as my EGC, although I have a spare conductor (8 are needed for the 4 strings) and I'll bond the green one to the equipment ground on the equipment end and the conduit body on the array end.

I'll be renting a small hydraulic bender if I can't find some 90 degree elbows in time for making the sweep upwards from the trench. I'm hoping I can adjust the overall length of the run slightly to avoid having to cut and thread the conduit before it runs into the C bodies on either end.

I've pulled a permit just for the cable installation, and am assuming I'll be calling for an inspection after the conduit is laid in the trench and then I've pulled the cable through it. (Of course before the trench is backfilled.)

The cable will be going into a dedicated steel equipment shed near but not attached to the house where all my disconnect, ground fault protection, charge controller, inverter/charger, and FLA goodies will be housed (and locked). Hopefully painting the thing all white and giving it some modest forced-air ventilation will keep things from getting too hot inside during the summertime. One nice thing about using a ground-mounted array and a "detached building that is only used to house PV equipment" is that NEC 2017 exempts you from both arc fault and rapid shutdown.

Comments welcome! (And in this forum, I say that knowing I might wind up receiving some harsh but realistic criticism of my plans. Plans are easier to change than hardware.)