My suggestion is to allow multiple "layers" of an IC chip.

Inside the IC chip would be an option to go down or up a layer. And there would also be a new component called a "Layered Wire" block, which is a wire that connects to any wires in the above/below layer.

This would mean you could definitely fit more components in the IC gate.

This is planned for next major update to the IC system.

This is being discussed here: #1616