A benefit for what purpose? If you're talking about defensive loads, just look at the Lucky Gunner ballistic tests which show data for .38 +P and .357 "short barrel" loads in 2" guns. There is a difference in the gel results, and that's about all we have for consensus on "benefits" for that purpose.
For example, look at the Speer Gold Dot 135 gr. "short barrel" 38 Spc. +P. The penetration averages a little over 13 inches, but the expansion is poor.
Now look at the Speer Gold Dot 135 gr. "short barrel" .357 Magnum. The penetration averages 13", but the expansion is very good.
The difference is in the velocity. 821 fps for .38 Spc. vs. 1069 fps for .357 Magnum.
Here's another comparison from the LG test. The BB 125 gr Barnes "low flash short barrel load" averaged 1144fps with penetration of 13.9 inches. Expansion was good on 4 out of 5 bullets and one bullet failed to expand. There's no direct comparison for .38 Special +P because those Barnes bullets require more velocity for dependable expansion. But let's compare a successful 125 gr. load. The best performing 125 grain .38+P from a 2" barrel in the test was the Remington Golden Saber. It averaged 877 fps, penetrated 13.9" and had good expansion. So based on this comparison, we'd have to say that "it depends." You could match or even better the performance of some "low flash short barrel" .357 Magnum using some .38 Sp. +P ammo, but it depends on the specific ammo used. We can see that "low flash" .357 still went 267 fps faster than .38+P and that extra velocity will allow some bullets to perform better. But if a bullet is used that isn't optimized for the purpose, there may be little or no benefit.
Your question didn't ask about non-"short-barrel" ammo in a short barrel. While short barrels do reduce the performance of .357 Magnum significantly, it should be understood that .357 Magnum ballistic performance is still very far ahead of .38 Special +P in a short barrel. The fastest .38 125 gr. load from a 2" barrel LG tested was 877 fps. The fastest 125 gr. .357 load from a 2" barrel was 1425 fps. .357 Magnum from a short barrel is still A LOT faster than .38 Special +P.
But more to your question, the "short-barrel" loads are intended to reduce flash and muzzle blast and improve the performance in ways that chronographs and gel blocks don't test. Those benefits may or may not be realized subjectively, and they may or may not result in good gel test results.
I can tell you from my experience developing loads and working with snub nosed revolvers for about a year, I've concluded that it's not worth it at all. The benefits of a longer barrel are numerous and there are no drawbacks. Short barrels (less than 3") are really a handicap in more ways than ballistic, and they offer no real benefits.