Blackcurrant do respond well to pruning, so I would be tempted to take out that top heavy branch. New growth should fruit next year... the wood darkens with age, so eventually, when you have several years' of branches grown, you know which are the oldest and can then cut these out to thin the bush down and keep it more open, as by then they are almost black.
And as you said, they grow really well from cuttings!