Well you can, and Plate Covers can have the Riveted Design too. They wont interfere with Multiblocks and they dont tick at all despite being TileEntities. Essentially as if you used GT6 Ore Blocks or Storage Blocks as decoration, or the Machine Casings.
Edit: Also that Fluid Display Item thing, I decided to not even require the Funnel or Nozzle for it to work, you can just rightclick a Tank with it and it fills it 100%, well or at least to 2^31 Millibuckets.