And I thought you had to set the layer 2 vertical scroll to none (which is what I did for the second half of my fifth castle, it's got the layer 2 smash 2 command, but instead of using the giant spiked logs, I used the blue thorns from Yoshi's Island in a cluster (2 blocks long by several blocks tall).
Anyway, when you're using one of the layer 2 smash commands, just remember that this effect will only happen on certain screens, and the further you go along, the faster they'll move.
Screens 01 and 02 (00 is the first screen as you know): the spikes move slowly, with plenty of time to dodge while they rise.
Screen 05: the spikes come down a little sooner after they rise.
Screens 07 and 08: the spikes begin to move a bit faster, at this point, proper timing becomes more important.
Screens 0B and 0C: the spikes move up and down quickly, you need to time your movements really well here.
