SSBM Target Test | Link【3.46】[TAS]
The reason this strategy is faster than the old one is that in this strategy, the first boomerang hits the target above the starting platform to the right. Consequently, the second boomerang can be thrown more horizontally and thus hit the last target slightly earlier.
The bomb is sent in a random direction after being hit by the arrow, which makes it a little bit more difficult to optimize (especially in conjunction with a pretty unstable emulator) so there might be reason to believe that 3.45 is possible with this strategy.