OP seems to be creating new problems rather than solving the first ones.
How about quantifying that 'voltage drop' statement and some description of where and how you ran your 10ga wire and what the vehicle is or length of run?
Then I'd suggest testing just the wire run for this 'drop'.
Then I'd suggest the use of some naked spade connectors and some heat shrink and then crimping AND soldering your connectors. Then measure your voltage at both the source and at the freshly soldered spade.
I really don't expect there to be any meaningful drop in a vehicle on such a run.
As to that ARB housing, if I judge it correctly there ought to be about 1" clear between the end of those socket spade connectors and the far wall of the enclosure. Should be enough room. Or use Flag style connectors, doesn't matter.
If you find it difficult to get the connectors on in that space, manipulate the connectors with some needle-nose pliers. Or better yet just loosen the ring on the socket and loosen and move it out of the enclosure while you get the wires seated. Then put humpty dumpty back together again.
But again, I have to ask 'what vehicle' - and why the choice of that enclosure? IF it's inside the back of a SUV or shell, why use that weather enclosure at all?
/my default answer is 'Anderson all the things'