Jefferson was kind of the Mao of his day; he thought knowledge was expanding so fast that each generation should redo the Constitution. He would have laughed at originalism, but he was an extremist on the subject. What about the others?
The Constitution was viewed, even by its strongest defenders, as a series of grubby compromises that only represented an incremental improvement over the status quo. None of the Founding Fathers got anything like what he really wanted in the process. And then, of course, there was the slavery issue.
Is it safe, therefore, to assume that the FFs would be astonished to hear that an America which looks nothing like the one they knew considers itself to be bound by their values on issues such as business regulations and guns? Yes, it is.