@obi_waynne , many thanks!!! These things:
are absolutely the cat's meow. WAGO has them up to five-gang, WMYCONGCONG (not sure how one pronounces that) has them up to eight-gang. They call them "Lever Nuts". They work for a huge range of wire gauges, are completely reusable, don't damage the stripped wire end at all, and seem nice and strong. Lift the lever, stick the wire in, drop the lever, done. I'm probably going to shoot a little dielectric grease in them for engine-compartment longevity, but that's it. Today I replaced all of my jury-rig tree of crimp-ons with lever nuts, re-using original wire (only needed about half!). I'll neaten up a lot more with new longer wires soon enough. Here's the before:
and the after, I'll get a better angle tomorrow:
I do get that it's hard to see the "neater" as of yet, but, less than half as many wires, less than a quarter as many connection nodes, all of the nodes lever-clamped not crimped, and no jury-rigged tree junctions where I had two or three wires jammed into one end of one of these:
And the wiring now has a fairly easily perceptible logic, groups of wires are logical and are daisy-chained, the negative in similar pattern as the positive. Much better than having to reverse engineer the trees every time