Wanted, garage heat!

[Speedfreak]

Went to Menards yesterday and checked out the csst stuff. Getting more comfortable with the diy option.

In trying to figure out where to place the heater, I have two good spots. Each would be sourcing the gas from a different ng gas line. Each would be from a similar junction (see pictures).

My question about the two junctions. They both have a cap at the same point, pointing toward the ground, near where they enter a furnace. Is this a valid point to take ng from? Just curious, as it seems like there is no reason to have those "T" junctions at those points other than maybe there is a reason for those caps at those points?