No replies and I do not know the answer.

Pity that the orchid has had a name change from Den. aggregatum to Den. lindleyi.

Plenty of old posts that as a joke referred to this orchid as Den. aggravation.

For some orchids the drought is overdone, drier rather than bone dry and the signal to bloom is a colder winter (but not freezing) followed by increasing day length and gentle warming up.