Personally i would Highley recommend
Sika 295UV sealant and
Skia Primer.
The primer makes a superb job of blackening the area where the sealer sits
and creates a chemical reaction to activate the sealant.
A lot of RV builders are sticking in canopy's and windows with this.
Used extensively for bonding in car windshields as well as bonding in windows into boats.
Our RV-7 had the canopy bonded in ten years ago and has no issues. So i went ahead bonded in the canopy and rear window with the 14