The standard way works with 99% of the pocket installations but you always have those special cases in our industry
The ceiling rafters are not leveled.
Add a washer or two between the bracket and the house framing when mounting the pocket to make the pocket leveled.
The finish material is 1/2 wood or other material thinner then drywall.
Run the wood blocks through a small planar to shave of whats needed.
The pocket needs to protrude out more.
Add a larger 3/8 washer or two between the bracket and the wood block.
The client changes the finish/thickness after drywall.
Unscrew the bolts, make the adjustments by thin the blocks or add some washers. Fasten the block/washers with some fast drying glue to make sure they don't move when remounting it. Because of the threaded bracket, its a fairly quick & easy process to do.
You are installing multiple heavy rollers for a sliding door system.
Add another mounting kit midpoint of the pocket.
You are installing the pocket right against the door system with no framing to attach to on one side.
Just cut of the short flange with a grinder and drill a whole through the bracket so the side closest to the door system can be fasten with a screw to the door header.
You are installing 2 pockets for a corner.
Cut the pockets 45 degrees like normal and then just have one block go all the way to the corner and the second block goes against the first block on the side.