1084 can certainly be differentially hardened. The hamon is most likely to be gently curving and rounded 'waves' so to speak, with not too much in the way of fine activity.
It's designed to be a deeper hardening steel with the addition of a fair amount of manganese which is kind of at adds with the formation of hamon.
1075, W2, W1 and 1095 are much shallower hardening steels with much less manganese and lacking other elements that aid in depth of hardening. These steels are capable of producing the more active 'wispy' and cloud-like hamon than 1084.