Hi JoshM,
Scott Jordan has seen and worked with you in person and they are very knowledgeable about their mattresses (NOTE ADDED: They are now a member of this site as well). I would never second guess whatever you decided together was best based on any “theory at a distance” when I haven’t seen you on a mattress myself. They know much more about what may be best for you when it comes to their own mattress designs than I would. I would trust what the two of you decided and if it needs to be changed once you’ve had the chance to sleep on it then based on your personal experience you have this option available. Your own testing and your own experience on a mattress will tell you much more than I could.
Post #89 here talks about the different types of protectors. These are top mattress protectors though which I would tend to prefer unless there is a compelling reason to choose the encasement type in which case you would be much more limited to a choice between a very tight weave fabric with a small micron size (@ 6 microns) such as these (less stretchy) or a membrane type encasement (similar to the ones that cover the top surface) but which surround the mattress (less breathable).
Phoenix