About pollen storage... Years ago Terry Root used to say that stored pollen did not give seedlings as good as doing the cross between to blooming plants. Paphanatics used to store their pollen, and they were very close to him however. Most breeders store their pollen.
However, I had the experience a couple of times with one year old pollen vs. fresh pollen of the same plant, and the seedlings indeed were different in the lab. In one case ( stored delenatii pollen), the seedlings were half the size of the ones made with the fresh pollen of the same plant. In nearly all others cases, I was not so happy with the quantity of germinating seeds or the seedling vigor.
If you want to store pollen of paphs, the best is to store them in transparent gelatine caps, keep only the gooey part, remove the hard part. It can stay like that for months or years. The gelatine caps is neither too dry nor too wet, and the pollen is still sticky after a couple of years. Fridge is fine, though I know people who froze it with success.
As to when to harvest the pollen, I watch it to become sticky and yellow color on the flower. Then it is ready to use. Some species can open up their flowers with immature pollen (like sangii, sometimes esquirolei...).
For parvis, I would say a week after opening, the pollen should be granular, but still soft, like a crymbly paste.
