There were actually at least 6 Super Dimension Fortress (SDF) vessels within the Macross universe.
1/ SDF-1 Macross (from Super Dimension Fortress Macross, Macross Plus, and Macross II)
2/ SDF-2 Megaroad-01 (from Macross Flashback 2012), even though the first Megaroad class ship had an SDF designation, there was no indication that the latter Megaroad ships (like Megaroad 13) ever did however
3/ SDF-6 Dark Queen II, this vessel has never been seen in any series, but has been referred to. Specifically, in an article that featured several VF-11 Thunderbolt squadron colors. There was one black VF-11 that had labelled on it the ship that it was assigned to, the SDF-6 Dark Queen II. No other infor other that was given. We can assume that it was active some time after 2030 (because VF-11s were introduced that year). There was an image posted on it a MW thread over a year ago regarding VF-11 Squadron colors (would any one still have a link to that thread or a copy of the image??)
4/ SDF-3 to -5, it is conjecture that these exist, to fill in the blank spaces between the SDF-2 and -6. This is similar to how the Excelsior class NCC-1701-B Enterprise was known to exist in Star Trek, despite the fact that it was not seen until Star Trek: Generations. There was an Enterprise-A (from Star Trek IV: The Voyage Home) and Enterprise-C (from 'Yesterday's Enterprise', ST: The Next Generation). The fact that it was an Excelsior class was from the montage of Enterprise models in Picard's office in ST:TNG.
EnterI can assume these exist