So butted spokes are nice because they stretch more (since they're thinner diameter in the middle, they stretch more for a given spoke tension than non-butted spokes of the same end-diameter). This means that when the rim deflects when the wheel hits a bump, spokes are less likely to lose tension.
This is particularly advantageous on the non-drive-side of dished rear wheels, where the spoke tension has to be relatively lower because of the dish. Broken spokes usually happen on the non-drive-side of the rear wheel because those are most likely to go out of tension as a result of rim deflection, and over many repetitions the spokes will flex back-and-forth at the elbow and eventually snap there.
I'm talking about straight 14g (2.0mm) spokes compared to 14/15/14 (2.0/1.8/2.0mm) butted spokes - these are the most common forms of straight-gauge and butted spokes.
Now, I'm wondering if there is much point of using butted spokes on the front wheel (non-disc wheel, no dish), or on the drive-side of the rear wheel. In both of these cases, spokes can be tensioned to the max safely allowable for the rim, and there is little to no chance of spokes ever losing tension as a result of rim deflection.
So, I'm wondering how much advantage butted spokes will give in the front wheel or rear drive-side? There are slight advantages in weight and aerodynamics, but are these even remotely relevant?
Thanks for any thoughts here.