The diverter sounds like a pretty good idea actually, it would be easy to do and more convenient than emptying the urine bottle, as that fills up fairly quick compared to the composting portion. It's not really a hassle now but it could be a cool project down the road. From what I've seen, it would be fine to do, this is from Nature's Head's own website "Where do I empty it? Urine is great for mature trees, or can be diluted for plants.". I always use organic soaps in the bus as well.
One random annoyance I discovered this weekend was the fridge being so close to the futon bed when it's folded down. The fridge is very quiet, but when it kicks on I can feel the vibrations in the bed! It's fine once I'm asleep, but it's one of those things where if you are about to drift off to sleep and it kicks on, it wakes you back up. So I might need to see if I can slide it over even 1/2" or maybe just put a foam pad on the bottom and edge. I'd also like to quiet the water pump down a bit, it's not bad really but I'd feel better about showering late at a quiet campsite if it were closer to silent. Looks like adding some padding, flexible tubing, and pipe insulation around some of the PEX should do the trick.
Here's a pic from this weekends outing, got the awning just in time! Also, the solar panels and Yeti are amazing, no worries about electric at all, and keeping the battery topped up at all times. Even after using the hot water heater, it's back to 100% in a couple of hours with good sun.