Yes, this question has been answered some few hundred times over the years. You could use cotton, soft cloth, gauze or other materials to wrap. Your penis are not circumcised. Do you pull back the foreskin or not ? The head are more sensitive in penises that are not «cut», so of course you will feel more, but there’s a possibility to extend with the foreskin in place, just wrap underneath the noose and be sure to loosen up the tightened noose every 15-20 minutes to allow blood flow to the foreskin and head.
It is important that the compressed extender is in the right length vs your flaccid stretched length. Put the extender upright on a table and put a ruler through the noose and base ring down to the table. Measure the length up to where the noose goes through the front piece of the extender. Measure your flaccid stretched out penis from base to just behind the head - they should be similar. The point is that when in the extender, the head of your penis should be almost in front of the extender, when the extender is compressed. In that way, when strapping in, the noose will do the job of securing your penis to the extender, and the extender will do the pulling, when you release it from the hand that is compressing it. In that way, the noose will not try to pull «through» the head like a hangman, and you will be able to have the noose a little bit less tight, and should be able to jelq some fresh blood into the head every 20 minutes while strapped in. In that way the head should not become so cold and numb and you can endure longer sets. Good luck.