Just keep in mind this is just my point of view … it would be awesome if it got added into future updates but i know it's unlikely to happen cause 1.0
… but hey maybe just some inspiration for a modder out there 
- VR like Blueprints making where player would be placed in to a grid space (like a tutorial background) where all ghosts will be immediately placed and could “spawn” in items on to belts as pleased basically creative mod and all of this inside the BP it self so everything u will do would be projected into the BP it self so updating a BP would be much much easier - just take a existing BP, place it in a VR-BP slot, click VR icon, update whatever u want, jump out and here u go updated BP
- Modular vehicles, cant talk for others but for me personally when making cars, tanks or whatever i usually make just one use that one until it breaks or most of the time it gets useless so it would be awesome if the vehicle could be modular in a way where u would make a shell of a vehicle and then once u place it u could choose what it will be inside the vehicle somewhat like a modular system in armor but once u make it thats it so u will have to choose weapons, what drives it more or less powerful engine i.e. early game (small) weaker or late game (bigger) stronger or even a electric motor where it will take power from a fusion reactor which will be required to install within the vehicle in the end once u configure it u would have to place certain items based on what u choose in to a trunk of the shell u placed and click build and here u go all custom vehicle just for u
After though: u could also push it a bit further where u would also pick a armor type or basically a visual skin where u could make a light and mobile car with big engine that would be just crazy fast or heavily armored but slower car or in late game have a different tank something bigger and heavier with even more HP it would open door to give player a bunch of stuff to play with without really crowding crafting menu also guess this might not be bad for modders since they could add all the vehicles they want through components for vehicles rather then fixed and set vehicles
and some less important but still useful IMO
-Undoing land filled area would be awesome we’re all people and make mistakes just a misclick and one has to reload
-Landfilling/paving over resources would “hide” them they would still be there but unmineable and invisible so u would have to remove the layer u placed before to mine them … or let them buried forever … or until someone else crashes on the same planet in million yrs and finds whatever remains of your factory
-Rocket turret … just a small 2x2 but rapid firing turret as a AOE upgrade from flamer basically a static spidertron
-Sideway inserter (rotatable I or O) imagine all the designs people could make with that being in vanilla
