I think a simple built-in help section or an item descriptor plus visual examples of uses would go a long ways.
It'd also be a decent game if the missions followed the nandgame path but with a focus on utilizing the different in/output for varying scenarios. A more tactile approach to the rather stale ones out. Given each map has large open spaces, there's enough room to hard-code in a sort of tutorial zone like a mechanics display where the player completes each step as a mission. At the end they have a line of contraptions that show what each component is does at a glance.
Resource management would be the biggest limiter on building anything of actual interest instead of just cleaning the map. There's not really much reason to build a whole suite of logic gates just to mine more of the finite blocks. The main draw of such a complex system is the hopes of building something complicated. Such an undertaking would take hundreds of units with their own nested/recursive units all with varying costs, I just can't see the current map sizes actually managing that. Rather than upscaling the world gen you can just make a renewable resource and crafting as the last bits of mission rewards. If you put them inside a unit then you would also save on clientside performance, staying loyal to the minimalist design.
*The first miner mission broke on me but I just assumed it was meant to put a piston on each output and hit complete afterwards. Miner 2 wasn't really a jump and more of a time consuming affair. Don't know what mover does and there weren't any new missions to skim hints from. Couldn't find any info on it, it also wasn't intuitive enough to figure out. Given the name I figured it synergizes with pistons somehow but for the life of me can't work out how.*