Explain your idea

Very simple suggestion, adding more blocks like the concrete sheet, which are carpet thickness versions of existing IE decorative/storage blocks. Something like concrete brick tiles, steel block tiles, sheetmetal flooring, etc. These would serve as a way to cheaply decorate your factory/base with metal flooring, something that is somewhat difficult in IE presently, since you either need to gather a very very large amount of metal and floor with blocks, or floor with slabs and get twice the mileage but also more hassle. These tile type blocks would also function as a convenient and aesthetic method of blocking both hostile and passive mob spawns (since like carpets they wouldn't count as full spawnable blocks), especially in caves where bats can spawn, or if using certain other mods with IE (cough cough Alex's mobs and their damn cockroaches). It'll also keep that damn trader away.
A good recipe could be 3 slabs of the relevant material in a line makes 24 of the carpet height equivalent, which would keep in line with the existing conversion rate of 1 concrete block makes 16 concrete sheets. 3 blocks -> 6 slabs -> 48 sheets, via the crafting table, keeping implementation and access simple.
Possible blocks:
sheetmetals -> metal flooring
metal blocks -> metal tiles (probably not uranium though)
treated wood -> hardwood flooring (this would be very nice)
concrete and hempcrete tile -> concrete and hempcrete flooring tile
concrete and hempcrete bricks -> concrete and hempcrete brick tiles
leaded concrete -> leaded concrete sheets (perhaps not this one)
hempcrete -> hempcrete sheets
scaffolding -> grate flooring
coke, blast, alloy kiln bricks -> coke, blast, alloy kiln brick tiles
coal coke blocks and insulating glass don't make much sense as flooring, but I think I've listed every other slab in IE already, so I may as well give names for these as well.
coal coke blocks -> coal coke flooring
insulating glass -> insulating glass sheet

Some of these could probably be given stonecutter recipes as well, but others aren't made of stone.

While concrete also has panels and 3/4 blocks, those probably aren't useful enough to justify adding a version for every decorative/semi-decorative block in IE. Carpet height blocks are useful enough for decoration imo however.