Fine tuning the location of an office chair on thick carpets
Go to your local plastics shop and get a quarter-inch polycarbonate plexi. They are usually clear, but you might find smoke or bronze. Bring a drawing of the T-shape that office units have. They will cut it and round the edges.
It is about the same cost as an office supply model, but you can customize it to match your office.
By the way, my home office chair stays in its dimples and I just rotate to get in or out. It took some fine-tuning to get the exact location.