They key is to wait until the plant starts to dry out on its own.
Try this...cut into a pod stem and let some of the (super sticky) white sap get on your hands. I swear that sap is the same thing they put in Elmer's glue.
At that stage, that sap is still within the pod to the extent that the floaters have sap residue on them. The floaters won't completely expand because the hairs stick together. There is a huge difference in how well a prime floater will drift compared to ones that were harvested before they were ready.
I picked a few pods about 3 or 4 weeks ago. They were plump and looked great. I put them in a food dehydrator for almost 48 hours. They came out dry, but the floaters just plain suck. Even weeks later, the floaters will not fully fluff and expand. Yeah, they float, but they still aren't as good as they will be when the pods are starting to dry on the plant. The difference in how well mature floaters will drift is dramatic.
Our pods are starting to look like the photo in the OP. They are starting to turn colors, so I decided to pick one yesterday. There is still a couple spots of sap oozing from a few pin-holes in the husk. The pods are getting closer to picking time, but if they are somewhat accessible to you, why pick them now? Wait until they naturally start to dry on the plant if you want premium floaters.