Yes, but they are heretics who deny the doctrines of grace.
You are saying that you can be Reformed and disagree with the Reformed Standards.
The FV say that they agree with the Reformed Standards insofar as they are biblical but disagree with them where they go against Scripture. They say that the Reformed Standards disagree with Scripture on x, y and z.
You say, the FV are heretics because they disagree with the Reformed Standards on x, y and z.
To which the FV cry, but our presbyteries have changed the Standards on x, y and z.
To which you reply....
The problem is that there needs to be a creed that is a standard, a canon of belief or doctrine. In Reformed circles these are the Westminster Standards and Three Forms of Unity (I would also add the Savoy declaration). Disagree with them and you are not Reformed.