there won’t be 3lbs difference in the frame.
300 grammes won’t really make any difference anyway.
oldgit, if you find a frame that you like and it is adequately stiff then go ahead. The differences are small even if they are perceptible and, as others have pointed out, there’s more to be gained performance-wise elsewhere.
More importantly, you would have the joy of appreciating it aesthetically every time you parked it up, washed it, rode it. On that score mrmo’s LeMond hits the spot for me. That’s a nice looking bike, lovely colours, something to be proud of.