I needed to move some 'lucifer' recently. I usualy dig crocosmia up asnd treat the clump of corms like one plant, diciding ito clumps when nessesary. But after the poot performance of one or two crocosmial clumps this year i decided to sperate the individual plants up and replant them wth more space between them. Still in a group to give a good show next summer, but with more room to grow. Hopefully the plants will flower better once they are reestablished. I intent to do this with the 'citronella' as well as any others in the garden that need lifting.
I do get the impression that like many bulbs and corms, crocosmia too flowere poorly if too overcrowded. The one i split up was certanly a very tightly packed group of corms.