I've always just tightened once... until..
There was the time when I bought a Phil titanium BB to use on a Campy Record crankset. i.e. the classic late 70's/early 80's Nuovo or Super Record crankset. I thought I'd replace the Campy BB with a lighter Phil BB. I contacted Phil to be sure that the axle taper was suited for the Campy, and they assured me it was. I installed it as typical, and did a few rides. Unfortunately, I was in the middle of a ride when I discovered that one (or both?) arms were a bit loose! I was close to one of the LBSs, and they snugged the bolts up. No issues after that.
My guess is that there was enough difference in the taper of the Campy axle and the Phil that the aluminum arms had to yield a bit before they fully contacted the axle taper. That, of course, meant that the bolts were no longer tight, and the crank arms were free to move around and deform the aluminum.
I had a chance to test this hypothesis when I bought some SunXCD cranks (clones of the TA Cyclotouriste) for a bike. I wasn't sure what BB to use, but had a Specialized cup & cone BB that looked like it was suitable. Since both the crank and BB were made in Japan, I figured that it should work. The test fit seemed fine. Still, for the first few weeks, I'd check the bolt torque after each ride. The first few rides did need a bit of additional torque, but after that, there was little or no change in bolt tension. A couple of years later, and no problems.
In my experience with good quality cranks that fit the axles, there shouldn't be any need to recheck bolt torque. On a brand new crank, it wouldn't be a bad idea to go check a few times, though.
Steve in Peoria