I would answer more generically
I never could get myself all excited about any magnum caliber round in snubbies, not even in rimfire or 32. (I would choose minimum of 3" for say, 22WMR or 32 H&R mag, but preferably 4")
Minimum 4" for general purpose, handles and carries real well, though I would still favor such as 38+P or 44 special in such, 5"-6" for range work or at home magnums
But.. if/when 6" still isn't enough sight radius to get the job done, well, that's why they make carbines. If you load up magnum level powder, might as well give it enough barrel to let the powder do it's work.
Sure, extra boost is extra boost, but it fades pretty quick as barrel length shrinks, rapidly diminishing returns, too much so to suit me.