Nope. Use flourish first and begin Standard Step around 5 seconds till pull. Hit Standard step next to boss (for 1000 potency) as your first attack of the pull. Rotate through the procs from flourish and use Cascade into Fountain (and procs) combo, saving any feathers generated so long as you don't cap and have a feather generating proc up. Begin technical step when standard step has approximately 8 seconds remaining before it comes off of cooldown. Use Standard step immediately after technical step(+10% damage to a 1000 potency nuke) and weave devilment as you hit with it. Begin to unload with OGCD weaving and your normal rotation. Saber dance becomes highest priority GCD during this time until standard step comes back up.
This is the selfish personal DPS opener. A case can be made for using Technical Step early with Ninja's Trick attack for greater benefit to the rest of the party's DPS.
Edit: I was jumping to conclusions based on the 20s you mention for standard step. So long as you fit it in the window of technical steps damage up, then yes you are right.
Dancer is designed to bank damage to unleash during a burst Window. Technical step and Devilment are both on a 2 minute cool down. So they should be aligned in that way for the greatest DPS you can contribute.
Standard step should be used on Cooldown at all times.