I did it on my AFB when I put the turbos on it in 2001.
Is it useful? Maybe.
If you've got a traditional hot rod or even a low 11 second street car then you're probably wasting your time.
Look at the size of the needles and seats. Is your engine going to be drawing the fuel faster than a 3/8" line at 5 psi can flow?
Probably not.

The crossover tube in the back of the air horn assembly is about 3/16" diameter. That has to flow enough to support a 1/10" needle and seat on the far side of the carb. 99% of the time that is a non-issue.

If you're slinging high G maneuvers like sustained cornering on road courses or autocrossing that might inhibit fuel flow through that tube then you should look at the dual feed.