I haven't used either product but would assume that there would be some sort of residue left behind in the unseen microscopic abrasions of the surface after the restoration process. A sealant of any type needs to adhere or crosslink to the surface it is applied to so you would want it to be crosslinking to the actual glass surface and not to the residue left behind on the glass from the restoration process. If it were me doing the work, I'd fare on the side of caution and use something like IPA or vinegar to fully clean the glass surface before applying any sealant to it.
