X2 on the cushion/metal clamps.
What people don't realize is all plastic clamps and including zip strips. There is a temperature rating written in small print on the package labels.
I'm sure the RV manuf buy the cheapest ones without regard to temp ratings.
I used zip stips to attached a canopy up North. When the temps fell I literally watched each and every one just crack open one by one. That is how 'I' found out about the high/low temp ratings on the labels.
The better the temp rating is the more expensive the zip strip cost was.