I can't comment on the Guatemalian tree fern. It will be for a different species compared to what we use in NZ and such it will probably require different management.
Your article was so helpful. This is new stuff to me. I didn't realize that NZ Tree Fern was a different product from the stiff twiggy stuff that can be bought in a bag, which is also "Tree Fern." but a different variety (from the New World?). I'm curious when NZ Tree Fern began to hit the orchid grower's market? It sounds great, and apparently a renewable resource.If you use a 100% NZ tree fern fibre you need to watch that you do not over water. I live in Auckland , New Zealand and in summer the watering interval would be between 4 to 7 days and for winter two to three weeks. The general rule of thumb is if in doubt , don't water.