Those look like excellent trails! I wish there were more steep hills like that around here - my bike loves them too. An '05 RM250 is pretty stiff competition, it's great the Zero kept up. I run 30% / 30% regen now - I can barely feel it kick in and braking is mostly from the brakes, which works best for me.
Re the shock - I guess you could just live with the bottoming, but if the spring rate is otherwise OK the best solution might be a new 2-stage bottoming bumper. I've never felt my 350-450 lb/in spring hard-bottom, but the bumper has definitely made repeated contact with the seal cap.
I had a different experience with Eco mode last week - I engaged it for an initial mud crossing, then forgot about it till I got home. My tires were shot and spinning a lot in Custom, so maybe w/less spin acceleration seemed about the same. I've got new Motoz Terrapactor S/T's on there now, can't wait to try 'em out tomorrow.
I pulled my headlight fuse and just use the running lights, but I never ride at night.
I couldn't find a shorty brake lever with an adjustable throw for my OEM MC, so I got an Emgo 30-64881 & shortened it myself (lever cut / ball end drilled out & JB Welded on / ground down). It worked pretty well.
Ray