The Cattleya 'rule' (= should dry out between waterings) is patently false. It dates back to a time when people overwatered and killed the roots.
Yes, I agree. In fact, I've made many videos saying as much!
That said, Lourens Grobler does say a drier period (not bone dry) is beneficial to Ansellia blooming. I was wondering if you had some experience with the species indicating otherwise.