I've searched for similar suggestions, but I didn't find any. Does not mean there weren't What I'm proposing is to add an option to add modules like solar panels, antennas, science instruments, ..., to staging. Every part could have an right click menu option "Add to staging" which would add appropriate icon to staging thingy, like currently engines, decouplers and fairings have. Additionally, it might be interesting to be able to add action groups to staging. This could improve mission planing