transplanting time for kerria japonica

Hi,
Kerria Japonica are, in my experience reasonably easy to divide and transplant. The roots usually spreadquite freely and you can just dig some out and transplant it. I would have thought Autumn was the best time. I have a 4 year old plant which I moved in October and it is now coming in to flower so it obviously didn't object to being moved.Spring is a good time to move plants usually but this plant presumably , is about to flower so best not to move now. Hope this helps. Regards Paul.