Scott wrote:
Would there be an argument for putting both leads into the same side,
so each terminal has two wires going into it, then the wires are in
physical contact and the space is better filled?

I don't have a preference, it depends on the space I'm putting it in.
If it's two cables coming in from the same side I'd put them into the
block side by side. If it's something coming in one end and going out
somewhere else I'd do it end to end, eg a neutral return passing
through a light switch, eg in the wiki:
http://wiki.diyfaq.org.uk/index.php/...tingWiring.gif