I would recommend against using silicone for radiator hoses. Its 15 times more permeable than rubber which makes them unsuitable for daily driving.

taken from another website:

"I can remember several occasions when people would tell me something like, “Dude I was driving the other day and my car started to boil over! I added 4 quarts of water to it! Did I lose a head gasket? Where the hell did the water go?” I would ask them if they had silicone radiator hoses and of course they would. So I told them, add water regularly or stop your *****ing and get some rubber hoses on the car. While silicone radiator hoses are great because they are capable of carrying much higher temperature fluids (max 350°F/177°C) than a standard EPDM rubber radiator hose (max 257°F/125°C), they are really only ideal for race cars. Here's a fun fact: silicone's water permeation rate is 15 times greater than EPDM rubber. What does that mean to you? It means with the daily heat cycling of a street driven car, that you will lose water from your cooling system over time. According to a Gates Corporation report, “Testing by Gates engineers shows that a Class 8 truck, operating at a temperature of 210°F with a two shift per day driving cycle, would lose nearly five gallons of water each year if it was equipped with silicone hose.” FYI, Gates makes both rubber and silicone coolant hoses so hold off on the forum bullshit line of, “Well of course Gates made that report. They sell rubber hoses!” If you want to read some more on this, check out a PDF pamphlet from Carquest here."

I've read this as well, not this exact article referenced though. I'm wondering if the hps 3 ply design prevents this? Im not entirely sure. The inner lining of these hoses is seemingly different than the outer lining. However I'm not sure about the materials used in the inner ply. I'll do some research on it!