I have no idea if the failure I saw on seals is typical, but the radius of the inflatible portion of he seal when the seal was vacuumed flat showed cracks due to age and flexing. Think of a round shape when inflated, and then press that round shape flat. That flat configuration is the shape of the inflatible portion when the slide is in motion or when there is no air pressure to seal the slide.

I have no idea how the seal can be treated with an anti aging or anti cracking compound (such as the materials used on de-icing boots on airplanes) because to access the seal an owner has to retract the slide about 2" past its normal closed position just to get at the seal. On my plane my de-icing boots were treated with a very expensive liquid called "Age-Master" which is about $200 a quart. The boots cost about $15,000 to replace and BFGoodrich clainms an average life of 7 years. My boots were 24 years old when I sold my plane and still had no patches or repairs so the life of rubber products can be extended but getting access every 3 to 6 months can be an issue.