Thinking about coating the threads in grease before fitting to help with any dirt once its on the road. Ive seen the 'socks' youve made there awesome!
the grease alone will help keep the surface oily & rust free for awhile till the water spray washes it off but exposed grease will also clog up with tons of dirt particles and potentially jam up the threads when you wanna adjust em later.
imho I'd both grease the threads to control rust plus make a tight fitting water proof jacket to shield most of the water & crap away from the assembly so it lasts as long as mine.
only thing i would ay anything bad about is the cutting of bulk head , looked a mess when finished,