How difficult would it be to add in the code from 'Landfill Everything' (https://mods.factorio.com/mod/LandfillEverything) to place a foundation tile under every relevant entity in a blueprint? That would GREATLY reduce the hassle of placing regular blueprints while using BRF.
(BTW, this great mod is a perfect match for 'Stable Foundations'. I suggest you mention that on the overview page.)
This feature does not work well with how the mod mechanic is implemented. Ghost tiles do not have a collision mask, which is required for entities (and their ghosts) to be placed. Unfortunately this is something I can't implement.