This mod adds a button that will put a landfill tile under every entity if you have a blueprint in hand. Very useful for complex reactor setups and blueprinting rail.
Ah, I need to separately register for the forums - I'll do that in a minute.
Your thread describes exactly why I made the mod - I couldn't find any convenient way to add landfill - or grass-1, which is the specific tile I'm placing. I hope you find it useful and let me know of any problems!