How about the cheap fiberglas drop ceiling panels? They are cheap, easy to cut, and provide some insulation. They are 24”x48”x1”. You could cut them a little wider than your joist and wedge them in place. One side is already white.
Get the truss documents. Even though you trust him now, you may not as the building progresses. I trusted mt contracted and cost me a fortune later on after finding major mistakes. Good peace of mind.
I just used the standard brass connectors on the side of my house at the driveway. Wifey can pull up, turn on the compressor from the outside switch and air up whatever she needs. No need to bother me.
I would make sure you brace your trusses as stated in your truss documents. Lots of times this is overlooked but is necessary. All the bracing is holding the trusses up and ties everything thing together. Makes for a much stronger structure.
Also might help to share your entire truss documents.
When I first got my cabinet I put in a whole 50# bag of black beauty. the media wouldn’t come out of the gun. Looked at everything 3 times. Took half of it out and it works perfect now.
I would build closer if you can. 200’ feet doesn’t seem that far but after your 5th trip out to the shop mid project because you keep forgetting something gets old.
Make sure when the trusses are set to read and install the bracing the engineered drawings spec out.
make sure you have plenty of 2x4 for bracing as you go. Don’t want to have to run ad get some with your crane waiting.