Storm33
30 degree spline are very common.
for high volume spline rolling, for moderate production spline hobbing and shaping , low to high volume spline grinding. I mostly work with mostly ANSI B92.i, again aircraft applications.
if the parts are high volume the tooling is relative inexpensive because the tooling is amortized by quantity of parts. the required quality and runout required will dictate the machining method.