I guess I missed the reel size/film size accommodation needed? Silicone spreads until it is one molecule thick and is essentially a slick contaminate. Long term it will migrate to lots of places you do not want it to go. Making an adaption for your 'limiting factors' might be a great adaption for others who have desire being thwarted by the same type of 'bedeviling assault' on their life quality. Developed an adapter for a truck driver once who had to hold re-bar with flat straps. Just a special adapter to couple the strap winch to a torque multiplier worked. An apron should be doable in most any suitable plastic film. One off or several. PM me if you chose.