Is it possible to split pdf rendering into boiler plate and greeting, for example?

Our application can create a lot of pdfs, each with a common boiler plate content and differing only by a greeting. But each pdf is created from scratch, so it takes a very long time to render a batch if you have dozens of them.

Is it possible to render the boiler plate once, render the several greetings separately and then merge them to create the separate pdfs? And if this is possible, would it be any faster than separately rendering each one?