I always preferred the 1 time insurance policy of sealing any install I did, water inside the cab is never a good thing.
Both products I use are made by 3M, Glazing & Bedding compound is a non hardening sealant used between the body and gasket. After the glass is in the gasket before the locking strip use Window Weld which is a urethane sealant placed between the glass and the gasket.
https://youtu.be/LsSB4Kad4qA this video gives you an idea where the sealants go.