There is an excellent article in AOS Orchid magazine about two months ago on New Zealand Sphag with Phals.
The recommendation was with pot sizes less than 4 inches I believe (but I am going on memory and
honestly, it could be 5 or 6 inches)
The New Zealand moss is suppose to dry from the bottom up; thus, when the top is dry or almost dry, you can reliably know it's time to water.
Larger pot sizes do not work as the media gets too packed centrally.
Of course, not sure how relevant this is since your media is a mixture of bark and NZsphag.
What you have essentially done, is increased the water retentive properties of your media by combining them as well as benefiting from the anti-bacterial properties of sphag moss.
I do not know if the moss will follow the same bottom up method of drying out especially when we know bark dries from the top down.
Consequently, the skewer method is a good way to go in judging when to water.
Your question about the packed sphag from the store is excellent. These plants are shipped across the Pacific and I'm sure go a great deal of time without water...possibly/hopefully in high humidity transport. Thus, packed sphag gets them to you looking pretty.
But ultimately, the packed sphag will suffocate the central root ball either from over watering after sold; or as the plant grows more roots.
Your media should be loose/snug as previously suggested.
It sounds like your plant is going to LOVE it's new home