They fill "gaps" or holes, so they fulfill a similar purpose.Not really since they don't do anything to fill the many gaps in Unicron's wings, or inside the planet mode teeth, or hands...
I would never use screw covers. I want to be able to fix things.
So far Ive:
*Taken out BoC
*Put BoC and Saber back together and put them back in Star Saber.
DNA Designs has a set coming. I love that bigger sword. Everything else, meh. I’m cool with the cannons. Don’t care about the faceplate. Wings are a too big IMO.