Is this DV?
There is no scaling. DV 4:3 is 720×480 and DV 16:9 is 720×480.
Of course, it scales it in the Final Cut viewer for your own viewing purposes, but that’s just an effect so you can get the proper view. The video itself is un-changed.
Meaning, you’re fine. Anamorphic is just a viewing mode you’re turning on or off. The video stays the same.
The 2 places where scaling comes into play:
1) If you make a 4:3 letterboxed video it will scale the video down to fit in the frame. This IS actually changing the pixels, but it’s shrinking it, not blowing it up, so there’s little to worry about here.
2) If you make an anamorphic DVD, the DVD player will either stretch it to fit a 16:9 tv or it will shrink it to fit a 4:3 TV. Either way, it’s the DVD player doing the work, so there’s nothing you can do to make it look any better or worse.