TL;DR
Rocket silo should have a 2x2 area exclusive for rocket parts, and the rest should be for inserting into the rocketWhat?
Having a segment specific only for rocket parts would allow one to insert blue circuit, low density structure and rocket fuel into the rocket with inserters In the picture above, one of the corners would have a visible segment for placing rocket parts, and everywhere else would just insert direct into its inventoryWhy?
Because it is impossible today to do it with inserters.One can make builds to insert items into rocket with inserters and logic circuit, but it is just impossible to insert if the item is part of the rocket part.