It was just a throw-away comment about a way of looking at why everything is bought in 1T units. It's certainly not worth bogging the topic down with. Essentially I think the idea of buying partial tonnage cargo adds nothing to the game other than decimal points. (But you realise you're applying "real life" to a sci-fi game?)
Yes, yes I do.
However in my defence it was in response to a rejection of non-tonnage quantities in order to improve 'immersion'.